Sidelink anchor group for sidelink position estimation

ABSTRACT

Disclosed are techniques for wireless communication. In an aspect, a position estimation entity provides assistance data to sidelink anchors and a UE. The assistance data may include a set of proximity-based sidelink positioning reference signal (PRS) pre-configurations for on-demand PRS position estimation. The target UE transmits a sidelink PRS trigger to trigger an on-demand sidelink PRS position estimation session with a dynamic sidelink anchor group, the sidelink PRS trigger configured to indicate a sidelink zone associated with the UE and a proximity requirement for participation in the on-demand sidelink PRS position estimation. At least one sidelink anchor determines that the proximity requirement to the sidelink zone is satisfied, selects a proximity-based sidelink PRS pre-configuration based on a dynamic proximity to the sidelink zone, and performs a sidelink PRS exchange with the UE.

BACKGROUND OF THE DISCLOSURE 1. Field of the Disclosure

Aspects of the disclosure relate generally to wireless communications.

2. Description of the Related Art

Wireless communication systems have developed through variousgenerations, including a first-generation analog wireless phone service(1G), a second-generation (2G) digital wireless phone service (includinginterim 2.5G and 2.75G networks), a third-generation (3G) high speeddata, Internet-capable wireless service and a fourth-generation (4G)service (e.g., Long Term Evolution (LTE) or WiMax). There are presentlymany different types of wireless communication systems in use, includingcellular and personal communications service (PCS) systems. Examples ofknown cellular systems include the cellular analog advanced mobile phonesystem (AMPS), and digital cellular systems based on code divisionmultiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), the Global System for Mobilecommunications (GSM), etc.

A fifth generation (5G) wireless standard, referred to as New Radio(NR), calls for higher data transfer speeds, greater numbers ofconnections, and better coverage, among other improvements. The 5Gstandard, according to the Next Generation Mobile Networks Alliance, isdesigned to provide data rates of several tens of megabits per second toeach of tens of thousands of users, with 1 gigabit per second to tens ofworkers on an office floor. Several hundreds of thousands ofsimultaneous connections should be supported in order to support largesensor deployments. Consequently, the spectral efficiency of 5G mobilecommunications should be significantly enhanced compared to the current4G standard. Furthermore, signaling efficiencies should be enhanced andlatency should be substantially reduced compared to current standards.

Leveraging the increased data rates and decreased latency of 5G, amongother things, vehicle-to-everything (V2X) communication technologies arebeing implemented to support autonomous driving applications, such aswireless communications between vehicles, between vehicles and theroadside infrastructure, between vehicles and pedestrians, etc.

SUMMARY

The following presents a simplified summary relating to one or moreaspects disclosed herein. Thus, the following summary should not beconsidered an extensive overview relating to all contemplated aspects,nor should the following summary be considered to identify key orcritical elements relating to all contemplated aspects or to delineatethe scope associated with any particular aspect. Accordingly, thefollowing summary has the sole purpose to present certain conceptsrelating to one or more aspects relating to the mechanisms disclosedherein in a simplified form to precede the detailed descriptionpresented below.

In an aspect, a method of operating a position estimation entityincludes performing sidelink anchor registration with a plurality ofsidelink anchors distributed throughout a plurality of sidelink zones;transmitting, to the plurality of sidelink anchors and a user equipment(UE), a set of proximity-based sidelink positioning reference signal(PRS) pre-configurations for on-demand PRS position estimation; andreceiving one or more measurement reports associated with an on-demandsidelink PRS position estimation session between the UE and a dynamicsidelink anchor group that is determined in accordance with the set ofproximity-based sidelink PRS pre-configurations.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, the method includes selecting the plurality of sidelinkanchors based on a sidelink anchor constraint that limits a number ofsidelink anchors assigned per sidelink zone.

In some aspects, the selection is based on one or more of UE capability,mobility status, power supply, position estimation accuracy, or acombination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a method of operating a user equipment (UE) includesreceiving, from a position estimation entity, a set of proximity-basedsidelink positioning reference signal (PRS) pre-configurations foron-demand PRS position estimation, the set of proximity-based sidelinkPRS pre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; transmitting asidelink PRS trigger to trigger an on-demand sidelink PRS positionestimation session with a dynamic sidelink anchor group, the sidelinkPRS trigger configured to indicate a sidelink zone associated with theUE and a proximity requirement for participation in the on-demandsidelink PRS position estimation; and performing a sidelink PRS exchangewith the dynamic sidelink anchor group in association with the on-demandsidelink PRS position estimation session based on one or moreproximity-based sidelink PRS pre-configurations from the set ofproximity-based sidelink PRS pre-configurations.

In some aspects, the method includes determining one or more beams forthe sidelink PRS exchange based on a spatial relationship between thesidelink zone associated with the UE and one or more sidelink zonesassociated with the dynamic sidelink anchor group.

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, the sidelink PRS exchange comprises blind decoding ordescrambling for sidelink PRS from the dynamic sidelink anchor group inaccordance with a zone-specific sequence, or the sidelink PRS exchangecomprises selective decoding or descrambling for sidelink PRS from thedynamic sidelink anchor group based on feedback to the sidelink PRStrigger from the dynamic sidelink anchor group.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, the plurality of sidelink anchors is distributed acrossthe plurality of sidelink zones based on a sidelink anchor constraintthat limits a number of sidelink anchors assigned per sidelink zone.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a method of operating a sidelink anchor includesperforming sidelink anchor registration with a position estimationentity; receiving, from the position estimation entity, a set ofproximity-based sidelink PRS pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; receiving, from auser equipment (UE), a sidelink PRS trigger to trigger an on-demandsidelink PRS position estimation session with a dynamic sidelink anchorgroup, the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; determining that thesidelink anchor satisfies the proximity requirement to the sidelinkzone; selecting at least one proximity-based sidelink PRSpre-configuration from the set of proximity-based sidelink PRSpre-configurations based on a proximity between the sidelink anchor andthe sidelink zone associated with the UE; performing a sidelink PRSexchange with the UE associated with the on-demand sidelink PRS positionestimation session based on the determination and in accordance with theat least one selected proximity-based sidelink PRS pre-configuration.

In some aspects, the method includes determining one or more beams forthe sidelink PRS exchange based on a spatial relationship between thesidelink zone associated with the UE and a sidelink zone associated withthe sidelink anchor.

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, the method includes transmitting a response to thesidelink PRS trigger to facilitate the sidelink PRS exchange between theUE and the sidelink anchor.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones, or the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters, or wherein the plurality of sidelinkanchors is distributed across the plurality of sidelink zones based on asidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone, or a combination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In an aspect, a position estimation entity includes a memory; at leastone transceiver; and at least one processor communicatively coupled tothe memory and the at least one transceiver, the at least one processorconfigured to: perform sidelink anchor registration with a plurality ofsidelink anchors distributed throughout a plurality of sidelink zones;transmit, via the at least one transceiver, to the plurality of sidelinkanchors and a user equipment (UE), a set of proximity-based sidelinkpositioning reference signal (PRS) pre-configurations for on-demand PRSposition estimation; and receive, via the at least one transceiver, oneor more measurement reports associated with an on-demand sidelink PRSposition estimation session between the UE and a dynamic sidelink anchorgroup that is determined in accordance with the set of proximity-basedsidelink PRS pre-configurations.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, the at least one processor is further configured to:select the plurality of sidelink anchors based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone.

In some aspects, the selection is based on one or more of UE capability,mobility status, power supply, position estimation accuracy, or acombination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a user equipment (UE) includes a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: receive, via the at least one transceiver, from aposition estimation entity, a set of proximity-based sidelinkpositioning reference signal (PRS) pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; transmit, via theat least one transceiver, a sidelink PRS trigger to trigger an on-demandsidelink PRS position estimation session with a dynamic sidelink anchorgroup, the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; and perform a sidelinkPRS exchange with the dynamic sidelink anchor group in association withthe on-demand sidelink PRS position estimation session based on one ormore proximity-based sidelink PRS pre-configurations from the set ofproximity-based sidelink PRS pre-configurations.

In some aspects, the at least one processor is further configured to:determine one or more beams for the sidelink PRS exchange based on aspatial relationship between the sidelink zone associated with the UEand one or more sidelink zones associated with the dynamic sidelinkanchor group.

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, the sidelink PRS exchange comprises blind decoding ordescrambling for sidelink PRS from the dynamic sidelink anchor group inaccordance with a zone-specific sequence, or the sidelink PRS exchangecomprises selective decoding or descrambling for sidelink PRS from thedynamic sidelink anchor group based on feedback to the sidelink PRStrigger from the dynamic sidelink anchor group.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, the plurality of sidelink anchors is distributed acrossthe plurality of sidelink zones based on a sidelink anchor constraintthat limits a number of sidelink anchors assigned per sidelink zone.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a sidelink anchor includes a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: perform sidelink anchor registration with a positionestimation entity; receive, via the at least one transceiver, from theposition estimation entity, a set of proximity-based sidelink PRSpre-configurations for on-demand PRS position estimation, the set ofproximity-based sidelink PRS pre-configurations associated with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; receive, via the at least one transceiver, from a userequipment (UE), a sidelink PRS trigger to trigger an on-demand sidelinkPRS position estimation session with a dynamic sidelink anchor group,the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; determine that thesidelink anchor satisfies the proximity requirement to the sidelinkzone; select at least one proximity-based sidelink PRS pre-configurationfrom the set of proximity-based sidelink PRS pre-configurations based ona proximity between the sidelink anchor and the sidelink zone associatedwith the UE; perform a sidelink PRS exchange with the UE associated withthe on-demand sidelink PRS position estimation session based on thedetermination and in accordance with the at least one selectedproximity-based sidelink PRS pre-configuration.

In some aspects, the at least one processor is further configured to:determine one or more beams for the sidelink PRS exchange based on aspatial relationship between the sidelink zone associated with the UEand a sidelink zone associated with the sidelink anchor.

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, the at least one processor is further configured to:transmit, via the at least one transceiver, a response to the sidelinkPRS trigger to facilitate the sidelink PRS exchange between the UE andthe sidelink anchor.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones, or the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters, or wherein the plurality of sidelinkanchors is distributed across the plurality of sidelink zones based on asidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone, or a combination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In an aspect, a position estimation entity includes means for performingsidelink anchor registration with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; means fortransmitting, to the plurality of sidelink anchors and a user equipment(UE), a set of proximity-based sidelink positioning reference signal(PRS) pre-configurations for on-demand PRS position estimation; andmeans for receiving one or more measurement reports associated with anon-demand sidelink PRS position estimation session between the UE and adynamic sidelink anchor group that is determined in accordance with theset of proximity-based sidelink PRS pre-configurations.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, the method includes means for selecting the pluralityof sidelink anchors based on a sidelink anchor constraint that limits anumber of sidelink anchors assigned per sidelink zone.

In some aspects, the selection is based on one or more of UE capability,mobility status, power supply, position estimation accuracy, or acombination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a user equipment (UE) includes means for receiving, from aposition estimation entity, a set of proximity-based sidelinkpositioning reference signal (PRS) pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; means fortransmitting a sidelink PRS trigger to trigger an on-demand sidelink PRSposition estimation session with a dynamic sidelink anchor group, thesidelink PRS trigger configured to indicate a sidelink zone associatedwith the UE and a proximity requirement for participation in theon-demand sidelink PRS position estimation; and means for performing asidelink PRS exchange with the dynamic sidelink anchor group inassociation with the on-demand sidelink PRS position estimation sessionbased on one or more proximity-based sidelink PRS pre-configurationsfrom the set of proximity-based sidelink PRS pre-configurations.

In some aspects, the method includes means for determining one or morebeams for the sidelink PRS exchange based on a spatial relationshipbetween the sidelink zone associated with the UE and one or moresidelink zones associated with the dynamic sidelink anchor group.

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, the sidelink PRS exchange comprises blind decoding ordescrambling for sidelink PRS from the dynamic sidelink anchor group inaccordance with a zone-specific sequence, or the sidelink PRS exchangecomprises selective decoding or descrambling for sidelink PRS from thedynamic sidelink anchor group based on feedback to the sidelink PRStrigger from the dynamic sidelink anchor group.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, the plurality of sidelink anchors is distributed acrossthe plurality of sidelink zones based on a sidelink anchor constraintthat limits a number of sidelink anchors assigned per sidelink zone.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a sidelink anchor includes means for performing sidelinkanchor registration with a position estimation entity; means forreceiving, from the position estimation entity, a set of proximity-basedsidelink PRS pre-configurations for on-demand PRS position estimation,the set of proximity-based sidelink PRS pre-configurations associatedwith a plurality of sidelink anchors distributed throughout a pluralityof sidelink zones; means for receiving, from a user equipment (UE), asidelink PRS trigger to trigger an on-demand sidelink PRS positionestimation session with a dynamic sidelink anchor group, the sidelinkPRS trigger configured to indicate a sidelink zone associated with theUE and a proximity requirement for participation in the on-demandsidelink PRS position estimation; means for determining that thesidelink anchor satisfies the proximity requirement to the sidelinkzone; means for selecting at least one proximity-based sidelink PRSpre-configuration from the set of proximity-based sidelink PRSpre-configurations based on a proximity between the sidelink anchor andthe sidelink zone associated with the UE; means for performing asidelink PRS exchange with the UE associated with the on-demand sidelinkPRS position estimation session based on the determination and inaccordance with the at least one selected proximity-based sidelink PRSpre-configuration.

In some aspects, the method includes means for determining one or morebeams for the sidelink PRS exchange based on a spatial relationshipbetween the sidelink zone associated with the UE and a sidelink zoneassociated with the sidelink anchor.

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, the method includes means for transmitting a responseto the sidelink PRS trigger to facilitate the sidelink PRS exchangebetween the UE and the sidelink anchor.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones, or the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters, or wherein the plurality of sidelinkanchors is distributed across the plurality of sidelink zones based on asidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone, or a combination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a positionestimation entity, cause the position estimation entity to: performsidelink anchor registration with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; transmit, to theplurality of sidelink anchors and a user equipment (UE), a set ofproximity-based sidelink positioning reference signal (PRS)pre-configurations for on-demand PRS position estimation; and receiveone or more measurement reports associated with an on-demand sidelinkPRS position estimation session between the UE and a dynamic sidelinkanchor group that is determined in accordance with the set ofproximity-based sidelink PRS pre-configurations.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, instructions that, when executed by position estimationentity, further cause the position estimation entity to:

In some aspects, the selection is based on one or more of UE capability,mobility status, power supply, position estimation accuracy, or acombination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a user equipment(UE), cause the UE to: receive, from a position estimation entity, a setof proximity-based sidelink positioning reference signal (PRS)pre-configurations for on-demand PRS position estimation, the set ofproximity-based sidelink PRS pre-configurations associated with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; transmit a sidelink PRS trigger to trigger an on-demandsidelink PRS position estimation session with a dynamic sidelink anchorgroup, the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; and perform a sidelinkPRS exchange with the dynamic sidelink anchor group in association withthe on-demand sidelink PRS position estimation session based on one ormore proximity-based sidelink PRS pre-configurations from the set ofproximity-based sidelink PRS pre-configurations.

In some aspects, instructions that, when executed by UE, further causethe UE to: determine one or more beams for the sidelink PRS exchangebased on a spatial relationship between the sidelink zone associatedwith the UE and one or more sidelink zones associated with the dynamicsidelink anchor group.

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, the sidelink PRS exchange comprises blind decoding ordescrambling for sidelink PRS from the dynamic sidelink anchor group inaccordance with a zone-specific sequence, or the sidelink PRS exchangecomprises selective decoding or descrambling for sidelink PRS from thedynamic sidelink anchor group based on feedback to the sidelink PRStrigger from the dynamic sidelink anchor group.

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

In some aspects, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

In some aspects, the plurality of sidelink anchors is distributed acrossthe plurality of sidelink zones based on a sidelink anchor constraintthat limits a number of sidelink anchors assigned per sidelink zone.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

In some aspects, the position estimation entity instructs the UE totrigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone, or the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

In an aspect, a non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a sidelinkanchor, cause the sidelink anchor to: perform sidelink anchorregistration with a position estimation entity; receive, from theposition estimation entity, a set of proximity-based sidelink PRSpre-configurations for on-demand PRS position estimation, the set ofproximity-based sidelink PRS pre-configurations associated with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; receive, from a user equipment (UE), a sidelink PRStrigger to trigger an on-demand sidelink PRS position estimation sessionwith a dynamic sidelink anchor group, the sidelink PRS triggerconfigured to indicate a sidelink zone associated with the UE and aproximity requirement for participation in the on-demand sidelink PRSposition estimation; determine that the sidelink anchor satisfies theproximity requirement to the sidelink zone; select at least oneproximity-based sidelink PRS pre-configuration from the set ofproximity-based sidelink PRS pre-configurations based on a proximitybetween the sidelink anchor and the sidelink zone associated with theUE; perform a sidelink PRS exchange with the UE associated with theon-demand sidelink PRS position estimation session based on thedetermination and in accordance with the at least one selectedproximity-based sidelink PRS pre-configuration.

In some aspects, instructions that, when executed by sidelink anchor,further cause the sidelink anchor to:

In some aspects, the proximity requirement designates a maximum distancefrom the sidelink zone associated with the UE, a minimum distance fromthe sidelink zone associated with the UE, or a combination thereof.

In some aspects, instructions that, when executed by sidelink anchor,further cause the sidelink anchor to:

In some aspects, the plurality of sidelink zones is associated with anon-public network (NPN).

In some aspects, each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

In some aspects, the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones, or the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters, or wherein the plurality of sidelinkanchors is distributed across the plurality of sidelink zones based on asidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone, or a combination thereof.

In some aspects, the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

Other objects and advantages associated with the aspects disclosedherein will be apparent to those skilled in the art based on theaccompanying drawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are presented to aid in the description ofvarious aspects of the disclosure and are provided solely forillustration of the aspects and not limitation thereof.

FIG. 1 illustrates an example wireless communications system, accordingto aspects of the disclosure.

FIGS. 2A and 2B illustrate example wireless network structures,according to aspects of the disclosure.

FIGS. 3A, 3B, and 3C are simplified block diagrams of several sampleaspects of components that may be employed in a user equipment (UE), abase station, and a network entity, respectively, and configured tosupport communications as taught herein.

FIG. 4 is a block diagram illustrating various components of an exampleuser equipment (UE), according to aspects of the disclosure.

FIG. 5 illustrates an example of a wireless communications system thatsupports unicast sidelink establishment, according to aspects of thedisclosure.

FIG. 6A illustrates one example of a TDD sidelink (PC5) resourceconfiguration in accordance with an aspect of the disclosure.

FIG. 6B illustrates an SCI-based resource reservation scheme inaccordance with an aspect of the disclosure.

FIG. 7 illustrates examples of various positioning methods, according toaspects of the disclosure.

FIG. 8 illustrates sidelink communication scheduling (or resourceallocation) schemes in accordance with aspects of the disclosure.

FIG. 9 illustrates an example wireless communication system in which avehicle user equipment (V-UE) is exchanging ranging signals with aroadside unit (RSU) and another V-UE, according to aspects of thedisclosure.

FIG. 10 illustrates other sidelink positioning schemes in accordancewith aspects of the disclosure.

FIG. 11 illustrates other UE distribution scenarios for sidelinkpositioning in accordance with aspects of the disclosure.

FIG. 12 illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIGS. 13-16 illustrate sidelink-assisted position estimation schemes inaccordance with aspects of the disclosure.

FIG. 17 illustrates a zone in accordance with a World Geodetic System 84(WSG84) model based on reference longitude and latitude coordinates(0,0) in accordance with an aspect of the disclosure.

FIG. 18 illustrates a sidelink zone topology in accordance with anaspect of the disclosure.

FIG. 19 illustrates an exemplary process of communication, according toaspects of the disclosure.

FIG. 20 illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 21 illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 22 illustrates an example implementation of the processes of FIGS.19-21 , respectively, in accordance with an aspect of the disclosure.

FIG. 23 illustrates a sidelink anchor group configuration in accordancewith aspects of the disclosure

FIG. 24 illustrates an exemplary process of communication, according toaspects of the disclosure.

FIG. 25 illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 26 illustrates an exemplary process of wireless communication,according to aspects of the disclosure.

FIG. 27 illustrates an example implementation of the processes of FIGS.24-26 , respectively, in accordance with an aspect of the disclosure.

FIG. 28 illustrates sidelink zone configurations in accordance withaspects of the disclosure.

FIG. 29 illustrates proximity-based sidelink PRS pre-configurations FORsidelink zone configurations in accordance with aspects of thedisclosure.

FIG. 30 illustrates a 25-zone configuration that includes 3 dead zones.

DETAILED DESCRIPTION

Aspects of the disclosure are provided in the following description andrelated drawings directed to various examples provided for illustrationpurposes. Alternate aspects may be devised without departing from thescope of the disclosure. Additionally, well-known elements of thedisclosure will not be described in detail or will be omitted so as notto obscure the relevant details of the disclosure.

The words “exemplary” and/or “example” are used herein to mean “servingas an example, instance, or illustration.” Any aspect described hereinas “exemplary” and/or “example” is not necessarily to be construed aspreferred or advantageous over other aspects. Likewise, the term“aspects of the disclosure” does not require that all aspects of thedisclosure include the discussed feature, advantage or mode ofoperation.

Those of skill in the art will appreciate that the information andsignals described below may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the description below may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof, depending inpart on the particular application, in part on the desired design, inpart on the corresponding technology, etc.

Further, many aspects are described in terms of sequences of actions tobe performed by, for example, elements of a computing device. It will berecognized that various actions described herein can be performed byspecific circuits (e.g., application specific integrated circuits(ASICs)), by program instructions being executed by one or moreprocessors, or by a combination of both. Additionally, the sequence(s)of actions described herein can be considered to be embodied entirelywithin any form of non-transitory computer-readable storage mediumhaving stored therein a corresponding set of computer instructions that,upon execution, would cause or instruct an associated processor of adevice to perform the functionality described herein. Thus, the variousaspects of the disclosure may be embodied in a number of differentforms, all of which have been contemplated to be within the scope of theclaimed subject matter. In addition, for each of the aspects describedherein, the corresponding form of any such aspects may be describedherein as, for example, “logic configured to” perform the describedaction.

As used herein, the terms “user equipment” (UE), “vehicle UE” (V-UE),“pedestrian user equipment (UE)” (P-UE), and “base station” are notintended to be specific or otherwise limited to any particular radioaccess technology (RAT), unless otherwise noted. In general, a UE may beany wireless communication device (e.g., vehicle on-board computer,vehicle navigation device, mobile phone, router, tablet computer, laptopcomputer, asset locating device, wearable (e.g., smartwatch, glasses,augmented reality (AR)/virtual reality (VR) headset, etc.), vehicle(e.g., automobile, motorcycle, bicycle, etc.), Internet of Things (IoT)device, etc.) used by a user to communicate over a wirelesscommunications network. A UE may be mobile or may (e.g., at certaintimes) be stationary, and may communicate with a radio access network(RAN). As used herein, the term “UE” may be referred to interchangeablyas a “mobile device,” an “access terminal” or “AT,” a “client device,” a“wireless device,” a “subscriber device,” a “subscriber terminal,” a“subscriber station,” a “user terminal” or UT, a “mobile terminal,” a“mobile station,” or variations thereof.

A V-UE is a type of UE and may be any in-vehicle wireless communicationdevice, such as a navigation system, a warning system, a heads-updisplay (HUD), an on-board computer, an in-vehicle infotainment system,an automated driving system (ADS), an advanced driver assistance system(ADAS), etc. Alternatively, a V-UE may be a portable wirelesscommunication device (e.g., a cell phone, tablet computer, etc.) that iscarried by the driver of the vehicle or a passenger in the vehicle. Theterm “V-UE” may refer to the in-vehicle wireless communication device orthe vehicle itself, depending on the context. A P-UE is a type of UE andmay be a portable wireless communication device that is carried by apedestrian (i.e., a user that is not driving or riding in a vehicle).Generally, UEs can communicate with a core network via a RAN, andthrough the core network the UEs can be connected with external networkssuch as the Internet and with other UEs. Of course, other mechanisms ofconnecting to the core network and/or the Internet are also possible forthe UEs, such as over wired access networks, wireless local area network(WLAN) networks (e.g., based on Institute of Electrical and ElectronicsEngineers (IEEE) 802.11, etc.) and so on.

A base station may operate according to one of several RATs incommunication with UEs depending on the network in which it is deployed,and may be alternatively referred to as an access point (AP), a networknode, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), aNew Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A basestation may be used primarily to support wireless access by UEsincluding supporting data, voice and/or signaling connections for thesupported UEs. In some systems a base station may provide purely edgenode signaling functions while in other systems it may provideadditional control and/or network management functions. A communicationlink through which UEs can send signals to a base station is called anuplink (UL) channel (e.g., a reverse traffic channel, a reverse controlchannel, an access channel, etc.). A communication link through whichthe base station can send signals to UEs is called a downlink (DL) orforward link channel (e.g., a paging channel, a control channel, abroadcast channel, a forward traffic channel, etc.). As used herein theterm traffic channel (TCH) can refer to either an UL/reverse orDL/forward traffic channel.

The term “base station” may refer to a single physicaltransmission-reception point (TRP) or to multiple physical TRPs that mayor may not be co-located. For example, where the term “base station”refers to a single physical TRP, the physical TRP may be an antenna ofthe base station corresponding to a cell (or several cell sectors) ofthe base station. Where the term “base station” refers to multipleco-located physical TRPs, the physical TRPs may be an array of antennas(e.g., as in a multiple-input multiple-output (MIMO) system or where thebase station employs beamforming) of the base station. Where the term“base station” refers to multiple non-co-located physical TRPs, thephysical TRPs may be a distributed antenna system (DAS) (a network ofspatially separated antennas connected to a common source via atransport medium) or a remote radio head (RRH) (a remote base stationconnected to a serving base station). Alternatively, the non-co-locatedphysical TRPs may be the serving base station receiving the measurementreport from the UE and a neighbor base station whose reference radiofrequency (RF) signals the UE is measuring. Because a TRP is the pointfrom which a base station transmits and receives wireless signals, asused herein, references to transmission from or reception at a basestation are to be understood as referring to a particular TRP of thebase station.

In some implementations that support positioning of UEs, a base stationmay not support wireless access by UEs (e.g., may not support data,voice, and/or signaling connections for UEs), but may instead transmitreference RF signals to UEs to be measured by the UEs and/or may receiveand measure signals transmitted by the UEs. Such base stations may bereferred to as positioning beacons (e.g., when transmitting RF signalsto UEs) and/or as location measurement units (e.g., when receiving andmeasuring RF signals from UEs).

An “RF signal” comprises an electromagnetic wave of a given frequencythat transports information through the space between a transmitter anda receiver. As used herein, a transmitter may transmit a single “RFsignal” or multiple “RF signals” to a receiver. However, the receivermay receive multiple “RF signals” corresponding to each transmitted RFsignal due to the propagation characteristics of RF signals throughmultipath channels. The same transmitted RF signal on different pathsbetween the transmitter and receiver may be referred to as a “multipath”RF signal. As used herein, an RF signal may also be referred to as a“wireless signal” or simply a “signal” where it is clear from thecontext that the term “signal” refers to a wireless signal or an RFsignal.

FIG. 1 illustrates an example wireless communications system 100,according to aspects of the disclosure. The wireless communicationssystem 100 (which may also be referred to as a wireless wide areanetwork (WWAN)) may include various base stations 102 (labelled “BS”)and various UEs 104. The base stations 102 may include macro cell basestations (high power cellular base stations) and/or small cell basestations (low power cellular base stations). In an aspect, the macrocell base stations 102 may include eNBs and/or ng-eNBs where thewireless communications system 100 corresponds to an LTE network, orgNBs where the wireless communications system 100 corresponds to a NRnetwork, or a combination of both, and the small cell base stations mayinclude femtocells, picocells, microcells, etc.

The base stations 102 may collectively form a RAN and interface with acore network 174 (e.g., an evolved packet core (EPC) or 5G core (5GC))through backhaul links 122, and through the core network 174 to one ormore location servers 172 (e.g., a location management function (LMF) ora secure user plane location (SUPL) location platform (SLP)). Thelocation server(s) 172 may be part of core network 174 or may beexternal to core network 174. In addition to other functions, the basestations 102 may perform functions that relate to one or more oftransferring user data, radio channel ciphering and deciphering,integrity protection, header compression, mobility control functions(e.g., handover, dual connectivity), inter-cell interferencecoordination, connection setup and release, load balancing, distributionfor non-access stratum (NAS) messages, NAS node selection,synchronization, RAN sharing, multimedia broadcast multicast service(MBMS), subscriber and equipment trace, RAN information management(RIM), paging, positioning, and delivery of warning messages. The basestations 102 may communicate with each other directly or indirectly(e.g., through the EPC/5GC) over backhaul links 134, which may be wiredor wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Eachof the base stations 102 may provide communication coverage for arespective geographic coverage area 110. In an aspect, one or more cellsmay be supported by a base station 102 in each geographic coverage area110. A “cell” is a logical communication entity used for communicationwith a base station (e.g., over some frequency resource, referred to asa carrier frequency, component carrier, carrier, band, or the like), andmay be associated with an identifier (e.g., a physical cell identifier(PCI), an enhanced cell identifier (ECI), a virtual cell identifier(VCI), a cell global identifier (CGI), etc.) for distinguishing cellsoperating via the same or a different carrier frequency. In some cases,different cells may be configured according to different protocol types(e.g., machine-type communication (MTC), narrowband IoT (NB-IoT),enhanced mobile broadband (eMBB), or others) that may provide access fordifferent types of UEs. Because a cell is supported by a specific basestation, the term “cell” may refer to either or both the logicalcommunication entity and the base station that supports it, depending onthe context. In some cases, the term “cell” may also refer to ageographic coverage area of a base station (e.g., a sector), insofar asa carrier frequency can be detected and used for communication withinsome portion of geographic coverage areas 110.

While neighboring macro cell base station 102 geographic coverage areas110 may partially overlap (e.g., in a handover region), some of thegeographic coverage areas 110 may be substantially overlapped by alarger geographic coverage area 110. For example, a small cell basestation 102′ (labelled “SC” for “small cell”) may have a geographiccoverage area 110′ that substantially overlaps with the geographiccoverage area 110 of one or more macro cell base stations 102. A networkthat includes both small cell and macro cell base stations may be knownas a heterogeneous network. A heterogeneous network may also includehome eNBs (HeNBs), which may provide service to a restricted group knownas a closed subscriber group (CSG).

The communication links 120 between the base stations 102 and the UEs104 may include uplink (also referred to as reverse link) transmissionsfrom a UE 104 to a base station 102 and/or downlink (DL) (also referredto as forward link) transmissions from a base station 102 to a UE 104.The communication links 120 may use MIMO antenna technology, includingspatial multiplexing, beamforming, and/or transmit diversity. Thecommunication links 120 may be through one or more carrier frequencies.Allocation of carriers may be asymmetric with respect to downlink anduplink (e.g., more or less carriers may be allocated for downlink thanfor uplink).

The wireless communications system 100 may further include a wirelesslocal area network (WLAN) access point (AP) 150 in communication withWLAN stations (STAs) 152 via communication links 154 in an unlicensedfrequency spectrum (e.g., 5 GHz). When communicating in an unlicensedfrequency spectrum, the WLAN STAs 152 and/or the WLAN AP 150 may performa clear channel assessment (CCA) or listen before talk (LBT) procedureprior to communicating in order to determine whether the channel isavailable.

The small cell base station 102′ may operate in a licensed and/or anunlicensed frequency spectrum. When operating in an unlicensed frequencyspectrum, the small cell base station 102′ may employ LTE or NRtechnology and use the same 5 GHz unlicensed frequency spectrum as usedby the WLAN AP 150. The small cell base station 102′, employing LTE/5Gin an unlicensed frequency spectrum, may boost coverage to and/orincrease capacity of the access network. NR in unlicensed spectrum maybe referred to as NR-U. LTE in an unlicensed spectrum may be referred toas LTE-U, licensed assisted access (LAA), or MulteFire.

The wireless communications system 100 may further include a mmW basestation 180 that may operate in millimeter wave (mmW) frequencies and/ornear mmW frequencies in communication with a UE 182. Extremely highfrequency (EHF) is part of the RF in the electromagnetic spectrum. EHFhas a range of 30 GHz to 300 GHz and a wavelength between 1 millimeterand 10 millimeters. Radio waves in this band may be referred to as amillimeter wave. Near mmW may extend down to a frequency of 3 GHz with awavelength of 100 millimeters. The super high frequency (SHF) bandextends between 3 GHz and 30 GHz, also referred to as centimeter wave.Communications using the mmW/near mmW radio frequency band have highpath loss and a relatively short range. The mmW base station 180 and theUE 182 may utilize beamforming (transmit and/or receive) over a mmWcommunication link 184 to compensate for the extremely high path lossand short range. Further, it will be appreciated that in alternativeconfigurations, one or more base stations 102 may also transmit usingmmW or near mmW and beamforming. Accordingly, it will be appreciatedthat the foregoing illustrations are merely examples and should not beconstrued to limit the various aspects disclosed herein.

Transmit beamforming is a technique for focusing an RF signal in aspecific direction. Traditionally, when a network node (e.g., a basestation) broadcasts an RF signal, it broadcasts the signal in alldirections (omni-directionally). With transmit beamforming, the networknode determines where a given target device (e.g., a UE) is located(relative to the transmitting network node) and projects a strongerdownlink RF signal in that specific direction, thereby providing afaster (in terms of data rate) and stronger RF signal for the receivingdevice(s). To change the directionality of the RF signal whentransmitting, a network node can control the phase and relativeamplitude of the RF signal at each of the one or more transmitters thatare broadcasting the RF signal. For example, a network node may use anarray of antennas (referred to as a “phased array” or an “antennaarray”) that creates a beam of RF waves that can be “steered” to pointin different directions, without actually moving the antennas.Specifically, the RF current from the transmitter is fed to theindividual antennas with the correct phase relationship so that theradio waves from the separate antennas add together to increase theradiation in a desired direction, while cancelling to suppress radiationin undesired directions.

Transmit beams may be quasi-co-located, meaning that they appear to thereceiver (e.g., a UE) as having the same parameters, regardless ofwhether or not the transmitting antennas of the network node themselvesare physically co-located. In NR, there are four types ofquasi-co-location (QCL) relations. Specifically, a QCL relation of agiven type means that certain parameters about a second reference RFsignal on a second beam can be derived from information about a sourcereference RF signal on a source beam. Thus, if the source reference RFsignal is QCL Type A, the receiver can use the source reference RFsignal to estimate the Doppler shift, Doppler spread, average delay, anddelay spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type B, the receivercan use the source reference RF signal to estimate the Doppler shift andDoppler spread of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type C, the receivercan use the source reference RF signal to estimate the Doppler shift andaverage delay of a second reference RF signal transmitted on the samechannel. If the source reference RF signal is QCL Type D, the receivercan use the source reference RF signal to estimate the spatial receiveparameter of a second reference RF signal transmitted on the samechannel.

In receive beamforming, the receiver uses a receive beam to amplify RFsignals detected on a given channel. For example, the receiver canincrease the gain setting and/or adjust the phase setting of an array ofantennas in a particular direction to amplify (e.g., to increase thegain level of) the RF signals received from that direction. Thus, when areceiver is said to beamform in a certain direction, it means the beamgain in that direction is high relative to the beam gain along otherdirections, or the beam gain in that direction is the highest comparedto the beam gain in that direction of all other receive beams availableto the receiver. This results in a stronger received signal strength(e.g., reference signal received power (RSRP), reference signal receivedquality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) ofthe RF signals received from that direction.

Transmit and receive beams may be spatially related. A spatial relationmeans that parameters for a second beam (e.g., a transmit or receivebeam) for a second reference signal can be derived from informationabout a first beam (e.g., a receive beam or a transmit beam) for a firstreference signal. For example, a UE may use a particular receive beam toreceive a reference downlink reference signal (e.g., synchronizationsignal block (SSB)) from a base station. The UE can then form a transmitbeam for sending an uplink reference signal (e.g., sounding referencesignal (SRS)) to that base station based on the parameters of thereceive beam.

Note that a “downlink” beam may be either a transmit beam or a receivebeam, depending on the entity forming it. For example, if a base stationis forming the downlink beam to transmit a reference signal to a UE, thedownlink beam is a transmit beam. If the UE is forming the downlinkbeam, however, it is a receive beam to receive the downlink referencesignal. Similarly, an “uplink” beam may be either a transmit beam or areceive beam, depending on the entity forming it. For example, if a basestation is forming the uplink beam, it is an uplink receive beam, and ifa UE is forming the uplink beam, it is an uplink transmit beam.

In 5G, the frequency spectrum in which wireless nodes (e.g., basestations 102/180, UEs 104/182) operate is divided into multiplefrequency ranges, FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). mmWfrequency bands generally include the FR2, FR3, and FR4 frequencyranges. As such, the terms “mmW” and “FR2” or “FR3” or “FR4” maygenerally be used interchangeably.

In a multi-carrier system, such as 5G, one of the carrier frequencies isreferred to as the “primary carrier” or “anchor carrier” or “primaryserving cell” or “PCell,” and the remaining carrier frequencies arereferred to as “secondary carriers” or “secondary serving cells” or“SCells.” In carrier aggregation, the anchor carrier is the carrieroperating on the primary frequency (e.g., FR1) utilized by a UE 104/182and the cell in which the UE 104/182 either performs the initial radioresource control (RRC) connection establishment procedure or initiatesthe RRC connection re-establishment procedure. The primary carriercarries all common and UE-specific control channels, and may be acarrier in a licensed frequency (however, this is not always the case).A secondary carrier is a carrier operating on a second frequency (e.g.,FR2) that may be configured once the RRC connection is establishedbetween the UE 104 and the anchor carrier and that may be used toprovide additional radio resources. In some cases, the secondary carriermay be a carrier in an unlicensed frequency. The secondary carrier maycontain only necessary signaling information and signals, for example,those that are UE-specific may not be present in the secondary carrier,since both primary uplink and downlink carriers are typicallyUE-specific. This means that different UEs 104/182 in a cell may havedifferent downlink primary carriers. The same is true for the uplinkprimary carriers. The network is able to change the primary carrier ofany UE 104/182 at any time. This is done, for example, to balance theload on different carriers. Because a “serving cell” (whether a PCell oran SCell) corresponds to a carrier frequency/component carrier overwhich some base station is communicating, the term “cell,” “servingcell,” “component carrier,” “carrier frequency,” and the like can beused interchangeably.

For example, still referring to FIG. 1 , one of the frequencies utilizedby the macro cell base stations 102 may be an anchor carrier (or“PCell”) and other frequencies utilized by the macro cell base stations102 and/or the mmW base station 180 may be secondary carriers(“SCells”). The simultaneous transmission and/or reception of multiplecarriers enables the UE 104/182 to significantly increase its datatransmission and/or reception rates. For example, two 20 MHz aggregatedcarriers in a multi-carrier system would theoretically lead to atwo-fold increase in data rate (i.e., 40 MHz), compared to that attainedby a single 20 MHz carrier.

In the example of FIG. 1 , any of the illustrated UEs (shown in FIG. 1as a single UE 104 for simplicity) may receive signals 124 from one ormore Earth orbiting space vehicles (SVs) 112 (e.g., satellites). In anaspect, the SVs 112 may be part of a satellite positioning system that aUE 104 can use as an independent source of location information. Asatellite positioning system typically includes a system of transmitters(e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) todetermine their location on or above the Earth based, at least in part,on positioning signals (e.g., signals 124) received from thetransmitters. Such a transmitter typically transmits a signal markedwith a repeating pseudo-random noise (PN) code of a set number of chips.While typically located in SVs 112, transmitters may sometimes belocated on ground-based control stations, base stations 102, and/orother UEs 104. A UE 104 may include one or more dedicated receiversspecifically designed to receive signals 124 for deriving geo locationinformation from the SVs 112.

In a satellite positioning system, the use of signals 124 can beaugmented by various satellite-based augmentation systems (SBAS) thatmay be associated with or otherwise enabled for use with one or moreglobal and/or regional navigation satellite systems. For example an SBASmay include an augmentation system(s) that provides integrityinformation, differential corrections, etc., such as the Wide AreaAugmentation System (WAAS), the European Geostationary NavigationOverlay Service (EGNOS), the Multi-functional Satellite AugmentationSystem (MSAS), the Global Positioning System (GPS) Aided Geo AugmentedNavigation or GPS and Geo Augmented Navigation system (GAGAN), and/orthe like. Thus, as used herein, a satellite positioning system mayinclude any combination of one or more global and/or regional navigationsatellites associated with such one or more satellite positioningsystems.

In an aspect, SVs 112 may additionally or alternatively be part of oneor more non-terrestrial networks (NTNs). In an NTN, an SV 112 isconnected to an earth station (also referred to as a ground station, NTNgateway, or gateway), which in turn is connected to an element in a 5Gnetwork, such as a modified base station 102 (without a terrestrialantenna) or a network node in a 5GC. This element would in turn provideaccess to other elements in the 5G network and ultimately to entitiesexternal to the 5G network, such as Internet web servers and other userdevices. In that way, a UE 104 may receive communication signals (e.g.,signals 124) from an SV 112 instead of, or in addition to, communicationsignals from a terrestrial base station 102.

Leveraging the increased data rates and decreased latency of NR, amongother things, vehicle-to-everything (V2X) communication technologies arebeing implemented to support intelligent transportation systems (ITS)applications, such as wireless communications between vehicles(vehicle-to-vehicle (V2V)), between vehicles and the roadsideinfrastructure (vehicle-to-infrastructure (V2I)), and between vehiclesand pedestrians (vehicle-to-pedestrian (V2P)). The goal is for vehiclesto be able to sense the environment around them and communicate thatinformation to other vehicles, infrastructure, and personal mobiledevices. Such vehicle communication will enable safety, mobility, andenvironmental advancements that current technologies are unable toprovide. Once fully implemented, the technology is expected to reduceunimpaired vehicle crashes by 80%.

Still referring to FIG. 1 , the wireless communications system 100 mayinclude multiple V-UEs 160 that may communicate with base stations 102over communication links 120 (e.g., using the Uu interface). V-UEs 160may also communicate directly with each other over a wireless sidelink162, with a roadside access point 164 (also referred to as a “roadsideunit”) over a wireless sidelink 166, or with UEs 104 over a wirelesssidelink 168. A wireless sidelink (or just “sidelink”) is an adaptationof the core cellular (e.g., LTE, NR) standard that allows directcommunication between two or more UEs without the communication needingto go through a base station. Sidelink communication may be unicast ormulticast, and may be used for device-to-device (D2D) media-sharing, V2Vcommunication, V2X communication (e.g., cellular V2X (cV2X)communication, enhanced V2X (eV2X) communication, etc.), emergencyrescue applications, etc. One or more of a group of V-UEs 160 utilizingsidelink communications may be within the geographic coverage area 110of a base station 102. Other V-UEs 160 in such a group may be outsidethe geographic coverage area 110 of a base station 102 or be otherwiseunable to receive transmissions from a base station 102. In some cases,groups of V-UEs 160 communicating via sidelink communications mayutilize a one-to-many (1:M) system in which each V-UE 160 transmits toevery other V-UE 160 in the group. In some cases, a base station 102facilitates the scheduling of resources for sidelink communications. Inother cases, sidelink communications are carried out between V-UEs 160without the involvement of a base station 102.

In an aspect, the sidelinks 162, 166, 168 may operate over a wirelesscommunication medium of interest, which may be shared with otherwireless communications between other vehicles and/or infrastructureaccess points, as well as other RATs. A “medium” may be composed of oneor more time, frequency, and/or space communication resources (e.g.,encompassing one or more channels across one or more carriers)associated with wireless communication between one or moretransmitter/receiver pairs.

In an aspect, the sidelinks 162, 166, 168 may be cV2X links. A firstgeneration of cV2X has been standardized in LTE, and the next generationis expected to be defined in NR. cV2X is a cellular technology that alsoenables device-to-device communications. In the U.S. and Europe, cV2X isexpected to operate in the licensed ITS band in sub-6 GHz. Other bandsmay be allocated in other countries. Thus, as a particular example, themedium of interest utilized by sidelinks 162, 166, 168 may correspond toat least a portion of the licensed ITS frequency band of sub-6 GHz.However, the present disclosure is not limited to this frequency band orcellular technology.

In an aspect, the sidelinks 162, 166, 168 may be dedicated short-rangecommunications (DSRC) links. DSRC is a one-way or two-way short-range tomedium-range wireless communication protocol that uses the wirelessaccess for vehicular environments (WAVE) protocol, also known as IEEE802.11p, for V2V, V2I, and V2P communications. IEEE 802.11p is anapproved amendment to the IEEE 802.11 standard and operates in thelicensed ITS band of 5.9 GHz (5.85-5.925 GHz) in the U.S. In Europe,IEEE 802.11p operates in the ITS G5A band (5.875-5.905 MHz). Other bandsmay be allocated in other countries. The V2V communications brieflydescribed above occur on the Safety Channel, which in the U.S. istypically a 10 MHz channel that is dedicated to the purpose of safety.The remainder of the DSRC band (the total bandwidth is 75 MHz) isintended for other services of interest to drivers, such as road rules,tolling, parking automation, etc. Thus, as a particular example, themediums of interest utilized by sidelinks 162, 166, 168 may correspondto at least a portion of the licensed ITS frequency band of 5.9 GHz.

Alternatively, the medium of interest may correspond to at least aportion of an unlicensed frequency band shared among various RATs.Although different licensed frequency bands have been reserved forcertain communication systems (e.g., by a government entity such as theFederal Communications Commission (FCC) in the United States), thesesystems, in particular those employing small cell access points, haverecently extended operation into unlicensed frequency bands such as theUnlicensed National Information Infrastructure (U-NII) band used bywireless local area network (WLAN) technologies, most notably IEEE802.11x WLAN technologies generally referred to as “Wi-Fi.” Examplesystems of this type include different variants of CDMA systems, TDMAsystems, FDMA systems, orthogonal FDMA (OFDMA) systems, single-carrierFDMA (SC-FDMA) systems, and so on.

Communications between the V-UEs 160 are referred to as V2Vcommunications, communications between the V-UEs 160 and the one or moreroadside access points 164 are referred to as V2I communications, andcommunications between the V-UEs 160 and one or more UEs 104 (where theUEs 104 are P-UEs) are referred to as V2P communications. The V2Vcommunications between V-UEs 160 may include, for example, informationabout the position, speed, acceleration, heading, and other vehicle dataof the V-UEs 160. The V2I information received at a V-UE 160 from theone or more roadside access points 164 may include, for example, roadrules, parking automation information, etc. The V2P communicationsbetween a V-UE 160 and a UE 104 may include information about, forexample, the position, speed, acceleration, and heading of the V-UE 160and the position, speed (e.g., where the UE 104 is carried by a user ona bicycle), and heading of the UE 104.

Note that although FIG. 1 only illustrates two of the UEs as V-UEs(V-UEs 160), any of the illustrated UEs (e.g., UEs 104, 152, 182, 190)may be V-UEs. In addition, while only the V-UEs 160 and a single UE 104have been illustrated as being connected over a sidelink, any of the UEsillustrated in FIG. 1 , whether V-UEs, P-UEs, etc., may be capable ofsidelink communication. Further, although only UE 182 was described asbeing capable of beam forming, any of the illustrated UEs, includingV-UEs 160, may be capable of beam forming. Where V-UEs 160 are capableof beam forming, they may beam form towards each other (i.e., towardsother V-UEs 160), towards roadside access points 164, towards other UEs(e.g., UEs 104, 152, 182, 190), etc. Thus, in some cases, V-UEs 160 mayutilize beamforming over sidelinks 162, 166, and 168.

The wireless communications system 100 may further include one or moreUEs, such as UE 190, that connects indirectly to one or morecommunication networks via one or more device-to-device (D2D)peer-to-peer (P2P) links. In the example of FIG. 1 , UE 190 has a D2DP2P link 192 with one of the UEs 104 connected to one of the basestations 102 (e.g., through which UE 190 may indirectly obtain cellularconnectivity) and a D2D P2P link 194 with WLAN STA 152 connected to theWLAN AP 150 (through which UE 190 may indirectly obtain WLAN-basedInternet connectivity). In an example, the D2D P2P links 192 and 194 maybe supported with any well-known D2D RAT, such as LTE Direct (LTE-D),WiFi Direct (WiFi-D), Bluetooth®, and so on. As another example, the D2DP2P links 192 and 194 may be sidelinks, as described above withreference to sidelinks 162, 166, and 168.

FIG. 2A illustrates an example wireless network structure 200. Forexample, a 5GC 210 (also referred to as a Next Generation Core (NGC))can be viewed functionally as control plane (C-plane) functions 214(e.g., UE registration, authentication, network access, gatewayselection, etc.) and user plane (U-plane) functions 212, (e.g., UEgateway function, access to data networks, IP routing, etc.) whichoperate cooperatively to form the core network. User plane interface(NG-U) 213 and control plane interface (NG-C) 215 connect the gNB 222 tothe 5GC 210 and specifically to the user plane functions 212 and controlplane functions 214, respectively. In an additional configuration, anng-eNB 224 may also be connected to the 5GC 210 via NG-C 215 to thecontrol plane functions 214 and NG-U 213 to user plane functions 212.Further, ng-eNB 224 may directly communicate with gNB 222 via a backhaulconnection 223. In some configurations, a Next Generation RAN (NG-RAN)220 may have one or more gNBs 222, while other configurations includeone or more of both ng-eNBs 224 and gNBs 222. Either (or both) gNB 222or ng-eNB 224 may communicate with one or more UEs 204 (e.g., any of theUEs described herein).

Another optional aspect may include a location server 230, which may bein communication with the 5GC 210 to provide location assistance forUE(s) 204. The location server 230 can be implemented as a plurality ofseparate servers (e.g., physically separate servers, different softwaremodules on a single server, different software modules spread acrossmultiple physical servers, etc.), or alternately may each correspond toa single server. The location server 230 can be configured to supportone or more location services for UEs 204 that can connect to thelocation server 230 via the core network, 5GC 210, and/or via theInternet (not illustrated). Further, the location server 230 may beintegrated into a component of the core network, or alternatively may beexternal to the core network (e.g., a third party server, such as anoriginal equipment manufacturer (OEM) server or service server).

FIG. 2B illustrates another example wireless network structure 250. A5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewedfunctionally as control plane functions, provided by an access andmobility management function (AMF) 264, and user plane functions,provided by a user plane function (UPF) 262, which operate cooperativelyto form the core network (i.e., 5GC 260). The functions of the AMF 264include registration management, connection management, reachabilitymanagement, mobility management, lawful interception, transport forsession management (SM) messages between one or more UEs 204 (e.g., anyof the UEs described herein) and a session management function (SMF)266, transparent proxy services for routing SM messages, accessauthentication and access authorization, transport for short messageservice (SMS) messages between the UE 204 and the short message servicefunction (SMSF) (not shown), and security anchor functionality (SEAF).The AMF 264 also interacts with an authentication server function (AUSF)(not shown) and the UE 204, and receives the intermediate key that wasestablished as a result of the UE 204 authentication process. In thecase of authentication based on a UMTS (universal mobiletelecommunications system) subscriber identity module (USIM), the AMF264 retrieves the security material from the AUSF. The functions of theAMF 264 also include security context management (SCM). The SCM receivesa key from the SEAF that it uses to derive access-network specific keys.The functionality of the AMF 264 also includes location servicesmanagement for regulatory services, transport for location servicesmessages between the UE 204 and a location management function (LMF) 270(which acts as a location server 230), transport for location servicesmessages between the NG-RAN 220 and the LMF 270, evolved packet system(EPS) bearer identifier allocation for interworking with the EPS, and UE204 mobility event notification. In addition, the AMF 264 also supportsfunctionalities for non-3GPP (Third Generation Partnership Project)access networks.

Functions of the UPF 262 include acting as an anchor point forintra-/inter-RAT mobility (when applicable), acting as an externalprotocol data unit (PDU) session point of interconnect to a data network(not shown), providing packet routing and forwarding, packet inspection,user plane policy rule enforcement (e.g., gating, redirection, trafficsteering), lawful interception (user plane collection), traffic usagereporting, quality of service (QoS) handling for the user plane (e.g.,uplink/downlink rate enforcement, reflective QoS marking in thedownlink), uplink traffic verification (service data flow (SDF) to QoSflow mapping), transport level packet marking in the uplink anddownlink, downlink packet buffering and downlink data notificationtriggering, and sending and forwarding of one or more “end markers” tothe source RAN node. The UPF 262 may also support transfer of locationservices messages over a user plane between the UE 204 and a locationserver, such as an SLP 272.

The functions of the SMF 266 include session management, UE Internetprotocol (IP) address allocation and management, selection and controlof user plane functions, configuration of traffic steering at the UPF262 to route traffic to the proper destination, control of part ofpolicy enforcement and QoS, and downlink data notification. Theinterface over which the SMF 266 communicates with the AMF 264 isreferred to as the N11 interface.

Another optional aspect may include an LMF 270, which may be incommunication with the 5GC 260 to provide location assistance for UEs204. The LMF 270 can be implemented as a plurality of separate servers(e.g., physically separate servers, different software modules on asingle server, different software modules spread across multiplephysical servers, etc.), or alternately may each correspond to a singleserver. The LMF 270 can be configured to support one or more locationservices for UEs 204 that can connect to the LMF 270 via the corenetwork, 5GC 260, and/or via the Internet (not illustrated). The SLP 272may support similar functions to the LMF 270, but whereas the LMF 270may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a controlplane (e.g., using interfaces and protocols intended to convey signalingmessages and not voice or data), the SLP 272 may communicate with UEs204 and external clients (not shown in FIG. 2B) over a user plane (e.g.,using protocols intended to carry voice and/or data like thetransmission control protocol (TCP) and/or IP).

User plane interface 263 and control plane interface 265 connect the 5GC260, and specifically the UPF 262 and AMF 264, respectively, to one ormore gNBs 222 and/or ng-eNBs 224 in the NG-RAN 220. The interfacebetween gNB(s) 222 and/or ng-eNB(s) 224 and the AMF 264 is referred toas the “N2” interface, and the interface between gNB(s) 222 and/orng-eNB(s) 224 and the UPF 262 is referred to as the “N3” interface. ThegNB(s) 222 and/or ng-eNB(s) 224 of the NG-RAN 220 may communicatedirectly with each other via backhaul connections 223, referred to asthe “Xn-C” interface. One or more of gNBs 222 and/or ng-eNBs 224 maycommunicate with one or more UEs 204 over a wireless interface, referredto as the “Uu” interface.

The functionality of a gNB 222 is divided between a gNB central unit(gNB-CU) 226 and one or more gNB distributed units (gNB-DUs) 228. Theinterface 232 between the gNB-CU 226 and the one or more gNB-DUs 228 isreferred to as the “F1” interface. A gNB-CU 226 is a logical node thatincludes the base station functions of transferring user data, mobilitycontrol, radio access network sharing, positioning, session management,and the like, except for those functions allocated exclusively to thegNB-DU(s) 228. More specifically, the gNB-CU 226 hosts the radioresource control (RRC), service data adaptation protocol (SDAP), andpacket data convergence protocol (PDCP) protocols of the gNB 222. AgNB-DU 228 is a logical node that hosts the radio link control (RLC),medium access control (MAC), and physical (PHY) layers of the gNB 222.Its operation is controlled by the gNB-CU 226. One gNB-DU 228 cansupport one or more cells, and one cell is supported by only one gNB-DU228. Thus, a UE 204 communicates with the gNB-CU 226 via the RRC, SDAP,and PDCP layers and with a gNB-DU 228 via the RLC, MAC, and PHY layers.

FIGS. 3A, 3B, and 3C illustrate several example components (representedby corresponding blocks) that may be incorporated into a UE 302 (whichmay correspond to any of the UEs described herein), a base station 304(which may correspond to any of the base stations described herein), anda network entity 306 (which may correspond to or embody any of thenetwork functions described herein, including the location server 230and the LMF 270, or alternatively may be independent from the NG-RAN 220and/or 5GC 210/260 infrastructure depicted in FIGS. 2A and 2B, such as aprivate network) to support the file transmission operations as taughtherein. It will be appreciated that these components may be implementedin different types of apparatuses in different implementations (e.g., inan ASIC, in a system-on-chip (SoC), etc.). The illustrated componentsmay also be incorporated into other apparatuses in a communicationsystem. For example, other apparatuses in a system may includecomponents similar to those described to provide similar functionality.Also, a given apparatus may contain one or more of the components. Forexample, an apparatus may include multiple transceiver components thatenable the apparatus to operate on multiple carriers and/or communicatevia different technologies.

The UE 302 and the base station 304 each include one or more wirelesswide area network (WWAN) transceivers 310 and 350, respectively,providing means for communicating (e.g., means for transmitting, meansfor receiving, means for measuring, means for tuning, means forrefraining from transmitting, etc.) via one or more wirelesscommunication networks (not shown), such as an NR network, an LTEnetwork, a GSM network, and/or the like. The WWAN transceivers 310 and350 may each be connected to one or more antennas 316 and 356,respectively, for communicating with other network nodes, such as otherUEs, access points, base stations (e.g., eNBs, gNBs), etc., via at leastone designated RAT (e.g., NR, LTE, GSM, etc.) over a wirelesscommunication medium of interest (e.g., some set of time/frequencyresources in a particular frequency spectrum). The WWAN transceivers 310and 350 may be variously configured for transmitting and encodingsignals 318 and 358 (e.g., messages, indications, information, and soon), respectively, and, conversely, for receiving and decoding signals318 and 358 (e.g., messages, indications, information, pilots, and soon), respectively, in accordance with the designated RAT. Specifically,the WWAN transceivers 310 and 350 may include one or more transmitters314 and 354, respectively, for transmitting and encoding signals 318 and358, respectively, and one or more receivers 312 and 352, respectively,for receiving and decoding signals 318 and 358, respectively.

The UE 302 and the base station 304 each also include, at least in somecases, one or more short-range wireless transceivers 320 and 360,respectively. The short-range wireless transceivers 320 and 360 may beconnected to one or more antennas 326 and 366, respectively, and providemeans for communicating (e.g., means for transmitting, means forreceiving, means for measuring, means for tuning, means for refrainingfrom transmitting, etc.) with other network nodes, such as other UEs,access points, base stations, etc., via at least one designated RAT(e.g., WiFi, LTE-D, Bluetooth®, Zigbee®, Z-Wave®, PC5, dedicatedshort-range communications (DSRC), wireless access for vehicularenvironments (WAVE), near-field communication (NFC), etc.) over awireless communication medium of interest. The short-range wirelesstransceivers 320 and 360 may be variously configured for transmittingand encoding signals 328 and 368 (e.g., messages, indications,information, and so on), respectively, and, conversely, for receivingand decoding signals 328 and 368 (e.g., messages, indications,information, pilots, and so on), respectively, in accordance with thedesignated RAT. Specifically, the short-range wireless transceivers 320and 360 may include one or more transmitters 324 and 364, respectively,for transmitting and encoding signals 328 and 368, respectively, and oneor more receivers 322 and 362, respectively, for receiving and decodingsignals 328 and 368, respectively. As specific examples, the short-rangewireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth®transceivers, Zigbee® and/or Z-Wave® transceivers, NFC transceivers, orvehicle-to-vehicle (V2V) and/or vehicle-to-everything (V2X)transceivers.

The UE 302 and the base station 304 also include, at least in somecases, satellite signal receivers 330 and 370. The satellite signalreceivers 330 and 370 may be connected to one or more antennas 336 and376, respectively, and may provide means for receiving and/or measuringsatellite positioning/communication signals 338 and 378, respectively.Where the satellite signal receivers 330 and 370 are satellitepositioning system receivers, the satellite positioning/communicationsignals 338 and 378 may be global positioning system (GPS) signals,global navigation satellite system (GLONASS) signals, Galileo signals,Beidou signals, Indian Regional Navigation Satellite System (NAVIC),Quasi-Zenith Satellite System (QZSS), etc. Where the satellite signalreceivers 330 and 370 are non-terrestrial network (NTN) receivers, thesatellite positioning/communication signals 338 and 378 may becommunication signals (e.g., carrying control and/or user data)originating from a 5G network. The satellite signal receivers 330 and370 may comprise any suitable hardware and/or software for receiving andprocessing satellite positioning/communication signals 338 and 378,respectively. The satellite signal receivers 330 and 370 may requestinformation and operations as appropriate from the other systems, and,at least in some cases, perform calculations to determine locations ofthe UE 302 and the base station 304, respectively, using measurementsobtained by any suitable satellite positioning system algorithm.

The base station 304 and the network entity 306 each include one or morenetwork transceivers 380 and 390, respectively, providing means forcommunicating (e.g., means for transmitting, means for receiving, etc.)with other network entities (e.g., other base stations 304, othernetwork entities 306). For example, the base station 304 may employ theone or more network transceivers 380 to communicate with other basestations 304 or network entities 306 over one or more wired or wirelessbackhaul links. As another example, the network entity 306 may employthe one or more network transceivers 390 to communicate with one or morebase station 304 over one or more wired or wireless backhaul links, orwith other network entities 306 over one or more wired or wireless corenetwork interfaces.

A transceiver may be configured to communicate over a wired or wirelesslink. A transceiver (whether a wired transceiver or a wirelesstransceiver) includes transmitter circuitry (e.g., transmitters 314,324, 354, 364) and receiver circuitry (e.g., receivers 312, 322, 352,362). A transceiver may be an integrated device (e.g., embodyingtransmitter circuitry and receiver circuitry in a single device) in someimplementations, may comprise separate transmitter circuitry andseparate receiver circuitry in some implementations, or may be embodiedin other ways in other implementations. The transmitter circuitry andreceiver circuitry of a wired transceiver (e.g., network transceivers380 and 390 in some implementations) may be coupled to one or more wirednetwork interface ports. Wireless transmitter circuitry (e.g.,transmitters 314, 324, 354, 364) may include or be coupled to aplurality of antennas (e.g., antennas 316, 326, 356, 366), such as anantenna array, that permits the respective apparatus (e.g., UE 302, basestation 304) to perform transmit “beamforming,” as described herein.Similarly, wireless receiver circuitry (e.g., receivers 312, 322, 352,362) may include or be coupled to a plurality of antennas (e.g.,antennas 316, 326, 356, 366), such as an antenna array, that permits therespective apparatus (e.g., UE 302, base station 304) to perform receivebeamforming, as described herein. In an aspect, the transmittercircuitry and receiver circuitry may share the same plurality ofantennas (e.g., antennas 316, 326, 356, 366), such that the respectiveapparatus can only receive or transmit at a given time, not both at thesame time. A wireless transceiver (e.g., WWAN transceivers 310 and 350,short-range wireless transceivers 320 and 360) may also include anetwork listen module (NLM) or the like for performing variousmeasurements.

As used herein, the various wireless transceivers (e.g., transceivers310, 320, 350, and 360, and network transceivers 380 and 390 in someimplementations) and wired transceivers (e.g., network transceivers 380and 390 in some implementations) may generally be characterized as “atransceiver,” “at least one transceiver,” or “one or more transceivers.”As such, whether a particular transceiver is a wired or wirelesstransceiver may be inferred from the type of communication performed.For example, backhaul communication between network devices or serverswill generally relate to signaling via a wired transceiver, whereaswireless communication between a UE (e.g., UE 302) and a base station(e.g., base station 304) will generally relate to signaling via awireless transceiver.

The UE 302, the base station 304, and the network entity 306 alsoinclude other components that may be used in conjunction with theoperations as disclosed herein. The UE 302, the base station 304, andthe network entity 306 include one or more processors 332, 384, and 394,respectively, for providing functionality relating to, for example,wireless communication, and for providing other processingfunctionality. The processors 332, 384, and 394 may therefore providemeans for processing, such as means for determining, means forcalculating, means for receiving, means for transmitting, means forindicating, etc. In an aspect, the processors 332, 384, and 394 mayinclude, for example, one or more general purpose processors, multi-coreprocessors, central processing units (CPUs), ASICs, digital signalprocessors (DSPs), field programmable gate arrays (FPGAs), otherprogrammable logic devices or processing circuitry, or variouscombinations thereof.

The UE 302, the base station 304, and the network entity 306 includememory circuitry implementing memories 340, 386, and 396 (e.g., eachincluding a memory device), respectively, for maintaining information(e.g., information indicative of reserved resources, thresholds,parameters, and so on). The memories 340, 386, and 396 may thereforeprovide means for storing, means for retrieving, means for maintaining,etc. In some cases, the UE 302, the base station 304, and the networkentity 306 may include on-demand PRS component 342, 388, and 398,respectively. The on-demand PRS component 342, 388, and 398 may behardware circuits that are part of or coupled to the processors 332,384, and 394, respectively, that, when executed, cause the UE 302, thebase station 304, and the network entity 306 to perform thefunctionality described herein. In other aspects, the on-demand PRScomponent 342, 388, and 398 may be external to the processors 332, 384,and 394 (e.g., part of a modem processing system, integrated withanother processing system, etc.). Alternatively, the on-demand PRScomponent 342, 388, and 398 may be memory modules stored in the memories340, 386, and 396, respectively, that, when executed by the processors332, 384, and 394 (or a modem processing system, another processingsystem, etc.), cause the UE 302, the base station 304, and the networkentity 306 to perform the functionality described herein. FIG. 3Aillustrates possible locations of the on-demand PRS component 342, whichmay be, for example, part of the one or more WWAN transceivers 310, thememory 340, the one or more processors 332, or any combination thereof,or may be a standalone component. FIG. 3B illustrates possible locationsof the on-demand PRS component 388, which may be, for example, part ofthe one or more WWAN transceivers 350, the memory 386, the one or moreprocessors 384, or any combination thereof, or may be a standalonecomponent. FIG. 3C illustrates possible locations of the on-demand PRScomponent 398, which may be, for example, part of the one or morenetwork transceivers 390, the memory 396, the one or more processors394, or any combination thereof, or may be a standalone component.

The UE 302 may include one or more sensors 344 coupled to the one ormore processors 332 to provide means for sensing or detecting movementand/or orientation information that is independent of motion dataderived from signals received by the one or more WWAN transceivers 310,the one or more short-range wireless transceivers 320, and/or thesatellite signal receiver 330. By way of example, the sensor(s) 344 mayinclude an accelerometer (e.g., a micro-electrical mechanical systems(MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), analtimeter (e.g., a barometric pressure altimeter), and/or any other typeof movement detection sensor. Moreover, the sensor(s) 344 may include aplurality of different types of devices and combine their outputs inorder to provide motion information. For example, the sensor(s) 344 mayuse a combination of a multi-axis accelerometer and orientation sensorsto provide the ability to compute positions in two-dimensional (2D)and/or three-dimensional (3D) coordinate systems.

In addition, the UE 302 includes a user interface 346 providing meansfor providing indications (e.g., audible and/or visual indications) to auser and/or for receiving user input (e.g., upon user actuation of asensing device such a keypad, a touch screen, a microphone, and so on).Although not shown, the base station 304 and the network entity 306 mayalso include user interfaces.

Referring to the one or more processors 384 in more detail, in thedownlink, IP packets from the network entity 306 may be provided to theprocessor 384. The one or more processors 384 may implementfunctionality for an RRC layer, a packet data convergence protocol(PDCP) layer, a radio link control (RLC) layer, and a medium accesscontrol (MAC) layer. The one or more processors 384 may provide RRClayer functionality associated with broadcasting of system information(e.g., master information block (MIB), system information blocks(SIBs)), RRC connection control (e.g., RRC connection paging, RRCconnection establishment, RRC connection modification, and RRCconnection release), inter-RAT mobility, and measurement configurationfor UE measurement reporting; PDCP layer functionality associated withheader compression/decompression, security (ciphering, deciphering,integrity protection, integrity verification), and handover supportfunctions; RLC layer functionality associated with the transfer of upperlayer PDUs, error correction through automatic repeat request (ARQ),concatenation, segmentation, and reassembly of RLC service data units(SDUs), re-segmentation of RLC data PDUs, and reordering of RLC dataPDUs; and MAC layer functionality associated with mapping betweenlogical channels and transport channels, scheduling informationreporting, error correction, priority handling, and logical channelprioritization.

The transmitter 354 and the receiver 352 may implement Layer-1 (L1)functionality associated with various signal processing functions.Layer-1, which includes a physical (PHY) layer, may include errordetection on the transport channels, forward error correction (FEC)coding/decoding of the transport channels, interleaving, rate matching,mapping onto physical channels, modulation/demodulation of physicalchannels, and MIMO antenna processing. The transmitter 354 handlesmapping to signal constellations based on various modulation schemes(e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying(QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation(M-QAM)). The coded and modulated symbols may then be split intoparallel streams. Each stream may then be mapped to an orthogonalfrequency division multiplexing (OFDM) subcarrier, multiplexed with areference signal (e.g., pilot) in the time and/or frequency domain, andthen combined together using an inverse fast Fourier transform (IFFT) toproduce a physical channel carrying a time domain OFDM symbol stream.The OFDM symbol stream is spatially precoded to produce multiple spatialstreams. Channel estimates from a channel estimator may be used todetermine the coding and modulation scheme, as well as for spatialprocessing. The channel estimate may be derived from a reference signaland/or channel condition feedback transmitted by the UE 302. Eachspatial stream may then be provided to one or more different antennas356. The transmitter 354 may modulate an RF carrier with a respectivespatial stream for transmission.

At the UE 302, the receiver 312 receives a signal through its respectiveantenna(s) 316. The receiver 312 recovers information modulated onto anRF carrier and provides the information to the one or more processors332. The transmitter 314 and the receiver 312 implement Layer-1functionality associated with various signal processing functions. Thereceiver 312 may perform spatial processing on the information torecover any spatial streams destined for the UE 302. If multiple spatialstreams are destined for the UE 302, they may be combined by thereceiver 312 into a single OFDM symbol stream. The receiver 312 thenconverts the OFDM symbol stream from the time-domain to the frequencydomain using a fast Fourier transform (FFT). The frequency domain signalcomprises a separate OFDM symbol stream for each subcarrier of the OFDMsignal. The symbols on each subcarrier, and the reference signal, arerecovered and demodulated by determining the most likely signalconstellation points transmitted by the base station 304. These softdecisions may be based on channel estimates computed by a channelestimator. The soft decisions are then decoded and de-interleaved torecover the data and control signals that were originally transmitted bythe base station 304 on the physical channel. The data and controlsignals are then provided to the one or more processors 332, whichimplements Layer-3 (L3) and Layer-2 (L2) functionality.

In the uplink, the one or more processors 332 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, and control signal processing to recover IPpackets from the core network. The one or more processors 332 are alsoresponsible for error detection.

Similar to the functionality described in connection with the downlinktransmission by the base station 304, the one or more processors 332provides RRC layer functionality associated with system information(e.g., MIB, SIBs) acquisition, RRC connections, and measurementreporting; PDCP layer functionality associated with headercompression/decompression, and security (ciphering, deciphering,integrity protection, integrity verification); RLC layer functionalityassociated with the transfer of upper layer PDUs, error correctionthrough ARQ, concatenation, segmentation, and reassembly of RLC SDUs,re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; andMAC layer functionality associated with mapping between logical channelsand transport channels, multiplexing of MAC SDUs onto transport blocks(TBs), demultiplexing of MAC SDUs from TBs, scheduling informationreporting, error correction through hybrid automatic repeat request(HARQ), priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator from a referencesignal or feedback transmitted by the base station 304 may be used bythe transmitter 314 to select the appropriate coding and modulationschemes, and to facilitate spatial processing. The spatial streamsgenerated by the transmitter 314 may be provided to different antenna(s)316. The transmitter 314 may modulate an RF carrier with a respectivespatial stream for transmission.

The uplink transmission is processed at the base station 304 in a mannersimilar to that described in connection with the receiver function atthe UE 302. The receiver 352 receives a signal through its respectiveantenna(s) 356. The receiver 352 recovers information modulated onto anRF carrier and provides the information to the one or more processors384.

In the uplink, the one or more processors 384 provides demultiplexingbetween transport and logical channels, packet reassembly, deciphering,header decompression, control signal processing to recover IP packetsfrom the UE 302. IP packets from the one or more processors 384 may beprovided to the core network. The one or more processors 384 are alsoresponsible for error detection.

For convenience, the UE 302, the base station 304, and/or the networkentity 306 are shown in FIGS. 3A, 3B, and 3C as including variouscomponents that may be configured according to the various examplesdescribed herein. It will be appreciated, however, that the illustratedcomponents may have different functionality in different designs. Inparticular, various components in FIGS. 3A to 3C are optional inalternative configurations and the various aspects includeconfigurations that may vary due to design choice, costs, use of thedevice, or other considerations. For example, in case of FIG. 3A, aparticular implementation of UE 302 may omit the WWAN transceiver(s) 310(e.g., a wearable device or tablet computer or PC or laptop may haveWi-Fi and/or Bluetooth capability without cellular capability), or mayomit the short-range wireless transceiver(s) 320 (e.g., cellular-only,etc.), or may omit the satellite signal receiver 330, or may omit thesensor(s) 344, and so on. In another example, in case of FIG. 3B, aparticular implementation of the base station 304 may omit the WWANtransceiver(s) 350 (e.g., a Wi-Fi “hotspot” access point withoutcellular capability), or may omit the short-range wirelesstransceiver(s) 360 (e.g., cellular-only, etc.), or may omit thesatellite receiver 370, and so on. For brevity, illustration of thevarious alternative configurations is not provided herein, but would bereadily understandable to one skilled in the art.

The various components of the UE 302, the base station 304, and thenetwork entity 306 may be communicatively coupled to each other overdata buses 334, 382, and 392, respectively. In an aspect, the data buses334, 382, and 392 may form, or be part of, a communication interface ofthe UE 302, the base station 304, and the network entity 306,respectively. For example, where different logical entities are embodiedin the same device (e.g., gNB and location server functionalityincorporated into the same base station 304), the data buses 334, 382,and 392 may provide communication between them.

The components of FIGS. 3A, 3B, and 3C may be implemented in variousways. In some implementations, the components of FIGS. 3A, 3B, and 3Cmay be implemented in one or more circuits such as, for example, one ormore processors and/or one or more ASICs (which may include one or moreprocessors). Here, each circuit may use and/or incorporate at least onememory component for storing information or executable code used by thecircuit to provide this functionality. For example, some or all of thefunctionality represented by blocks 310 to 346 may be implemented byprocessor and memory component(s) of the UE 302 (e.g., by execution ofappropriate code and/or by appropriate configuration of processorcomponents). Similarly, some or all of the functionality represented byblocks 350 to 388 may be implemented by processor and memorycomponent(s) of the base station 304 (e.g., by execution of appropriatecode and/or by appropriate configuration of processor components). Also,some or all of the functionality represented by blocks 390 to 398 may beimplemented by processor and memory component(s) of the network entity306 (e.g., by execution of appropriate code and/or by appropriateconfiguration of processor components). For simplicity, variousoperations, acts, and/or functions are described herein as beingperformed “by a UE,” “by a base station,” “by a network entity,” etc.However, as will be appreciated, such operations, acts, and/or functionsmay actually be performed by specific components or combinations ofcomponents of the UE 302, base station 304, network entity 306, etc.,such as the processors 332, 384, 394, the transceivers 310, 320, 350,and 360, the memories 340, 386, and 396, the on-demand PRS component342, 388, and 398, etc.

In some designs, the network entity 306 may be implemented as a corenetwork component. In other designs, the network entity 306 may bedistinct from a network operator or operation of the cellular networkinfrastructure (e.g., NG RAN 220 and/or 5GC 210/260). For example, thenetwork entity 306 may be a component of a private network that may beconfigured to communicate with the UE 302 via the base station 304 orindependently from the base station 304 (e.g., over a non-cellularcommunication link, such as WiFi).

Note that the UE 302 illustrated in FIG. 3A may represent a “low-tier”UE or a “premium” UE. As described further below, while low-tier andpremium UEs may have the same types of components (e.g., both may haveWWAN transceivers 310, processing systems 332, memory components 340,etc.), the components may have different degrees of functionality (e.g.,increased or decreased performance, more or fewer capabilities, etc.)depending on whether the UE 302 corresponds to a low-tier UE or apremium UE.

UEs may be classified as low-tier UEs (e.g., wearables, such as smartwatches, glasses, rings, etc.) and premium UEs (e.g., smartphones,tablet computers, laptop computers, etc.). Low-tier UEs mayalternatively be referred to as reduced-capability NR UEs,reduced-capability UEs, NR light UEs, light UEs, NR super light UEs, orsuper light UEs. Premium UEs may alternatively be referred to asfull-capability UEs or simply UEs. Low-tier UEs generally have lowerbaseband processing capability, fewer antennas (e.g., one receiverantenna as baseline in FR1 or FR2, two receiver antennas optionally),lower operational bandwidth capabilities (e.g., 20 MHz for FR1 with nosupplemental uplink or carrier aggregation, or 50 or 100 MHz for FR2),only half duplex frequency division duplex (HD-FDD) capability, smallerHARQ buffer, reduced physical downlink control channel (PDCCH)monitoring, restricted modulation (e.g., 64 QAM for downlink and 16 QAMfor uplink), relaxed processing timeline requirements, and/or loweruplink transmission power compared to premium UEs. Different UE tierscan be differentiated by UE category and/or by UE capability. Forexample, certain types of UEs may be assigned a classification (e.g., bythe original equipment manufacturer (OEM), the applicable wirelesscommunications standards, or the like) of “low-tier” and other types ofUEs may be assigned a classification of “premium.” Certain tiers of UEsmay also report their type (e.g., “low-tier” or “premium”) to thenetwork. Additionally, certain resources and/or channels may bededicated to certain types of UEs.

As will be appreciated, the accuracy of low-tier UE positioning may belimited. For example, a low-tier UE may operate on a reduced bandwidth,such as 5 to 20 MHz for wearable devices and “relaxed” IoT devices(i.e., IoT devices with relaxed, or lower, capability parameters, suchas lower throughput, relaxed delay requirements, lower energyconsumption, etc.), which results in lower positioning accuracy. Asanother example, a low-tier UE's receive processing capability may belimited due to its lower cost RF/baseband. As such, the reliability ofmeasurements and positioning computations would be reduced. In addition,such a low-tier UE may not be able to receive multiple PRS from multipleTRPs, further reducing positioning accuracy. As yet another example, thetransmit power of a low-tier UE may be reduced, meaning there would be alower quality of uplink measurements for low-tier UE positioning.

Premium UEs generally have a larger form factor and are costlier thanlow-tier UEs, and have more features and capabilities than low-tier UEs.For example, with respect to positioning, a premium UE may operate onthe full PRS bandwidth, such as 100 MHz, and measure PRS from more TRPsthan low-tier UEs, both of which result in higher positioning accuracy.As another example, a premium UE's receive processing capability may behigher (e.g., faster) due to its higher-capability RF/baseband. Inaddition, the transmit power of a premium UE may be higher than that ofa low-tier UE. As such, the reliability of measurements and positioningcomputations would be increased.

FIG. 4 is a block diagram illustrating various components of an exampleUE 400, according to aspects of the disclosure. In an aspect, the UE 400may correspond to any of the UEs described herein (e.g., an exampleimplementation of UE 302, etc.). As a specific example, the UE 400 maybe a V-UE, such as V-UE 160 in FIG. 1 . For the sake of simplicity, thevarious features and functions illustrated in the block diagram of FIG.4 are connected together using a common data bus that is meant torepresent that these various features and functions are operativelycoupled together. Those skilled in the art will recognize that otherconnections, mechanisms, features, functions, or the like, may beprovided and adapted as necessary to operatively couple and configure anactual UE. Further, it is also recognized that one or more of thefeatures or functions illustrated in the example of FIG. 4 may befurther subdivided, or two or more of the features or functionsillustrated in FIG. 4 may be combined.

The UE 400 may include at least one transceiver 404 connected to one ormore antennas 402 and providing means for communicating (e.g., means fortransmitting, means for receiving, means for measuring, means fortuning, means for refraining from transmitting, etc.) with other networknodes, such as V-UEs (e.g., V-UEs 160), infrastructure access points(e.g., roadside access point 164), P-UEs (e.g., UEs 104), base stations(e.g., base stations 102), etc., via at least one designated RAT (e.g.,cV2X or IEEE 802.11p) over one or more communication links (e.g.,communication links 120, sidelinks 162, 166, 168, mmW communication link184). The at least one transceiver 404 may be variously configured fortransmitting and encoding signals (e.g., messages, indications,information, and so on), and, conversely, for receiving and decodingsignals (e.g., messages, indications, information, pilots, and so on) inaccordance with the designated RAT. In an aspect, the at least onetransceiver 404 and the antenna(s) 402 may form a (wireless)communication interface of the UE 400.

As used herein, a “transceiver” may include at least one transmitter andat least one receiver in an integrated device (e.g., embodied as atransmitter circuit and a receiver circuit of a single communicationdevice) in some implementations, may comprise a separate transmitterdevice and a separate receiver device in some implementations, or may beembodied in other ways in other implementations. In an aspect, atransmitter may include or be coupled to a plurality of antennas (e.g.,antenna(s) 402), such as an antenna array, that permits the UE 400 toperform transmit “beamforming,” as described herein. Similarly, areceiver may include or be coupled to a plurality of antennas (e.g.,antenna(s) 402), such as an antenna array, that permits the UE 400 toperform receive beamforming, as described herein. In an aspect, thetransmitter(s) and receiver(s) may share the same plurality of antennas(e.g., antenna(s) 402), such that the UE 400 can only receive ortransmit at a given time, not both at the same time. In some cases, atransceiver may not provide both transmit and receive functionalities.For example, a low functionality receiver circuit may be employed insome designs to reduce costs when providing full communication is notnecessary (e.g., a receiver chip or similar circuitry simply providinglow-level sniffing).

The UE 400 may also include a satellite positioning system (SPS)receiver 406. The SPS receiver 406 may be connected to one or more SPSantennas 403 and may provide means for receiving and/or measuringsatellite signals. The SPS receiver 406 may comprise any suitablehardware and/or software for receiving and processing SPS signals, suchas global positioning system (GPS) signals. The SPS receiver 406requests information and operations as appropriate from the othersystems, and performs the calculations necessary to determine the UE's400 position using measurements obtained by any suitable SPS algorithm.

One or more sensors 408 may be coupled to at least one processor 410 andmay provide means for sensing or detecting information related to thestate and/or environment of the UE 400, such as speed, heading (e.g.,compass heading), headlight status, gas mileage, etc. By way of example,the one or more sensors 408 may include a speedometer, a tachometer, anaccelerometer (e.g., a microelectromechanical systems (MEMS) device), agyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., abarometric pressure altimeter), etc.

The at least one processor 410 may include one or more centralprocessing units (CPUs), microprocessors, microcontrollers, ASICs,processing cores, digital signal processors (DSPs), field-programmablegate arrays (FPGAs), or the like that provide processing functions, aswell as other calculation and control functionality. The at least oneprocessor 410 may therefore provide means for processing, such as meansfor determining, means for calculating, means for receiving, means fortransmitting, means for indicating, etc. The at least one processor 410may include any form of logic suitable for performing, or causing thecomponents of the UE 400 to perform, at least the techniques describedherein.

The at least one processor 410 may also be coupled to a memory 414providing means for storing (including means for retrieving, means formaintaining, etc.) data and software instructions for executingprogrammed functionality within the UE 400. The memory 414 may beon-board the at least one processor 410 (e.g., within the sameintegrated circuit (IC) package), and/or the memory 414 may be externalto the at least one processor 410 and functionally coupled over a databus.

The UE 400 may include a user interface 450 that provides any suitableinterface systems, such as a microphone/speaker 452, keypad 454, anddisplay 456 that allow user interaction with the UE 400. Themicrophone/speaker 452 may provide for voice communication services withthe UE 400. The keypad 454 may comprise any suitable buttons for userinput to the UE 400. The display 456 may comprise any suitable display,such as, for example, a backlit liquid crystal display (LCD), and mayfurther include a touch screen display for additional user input modes.The user interface 450 may therefore be a means for providingindications (e.g., audible and/or visual indications) to a user and/orfor receiving user input (e.g., via user actuation of a sensing devicesuch a keypad, a touch screen, a microphone, and so on).

In an aspect, the UE 400 may include a sidelink manager 470 coupled tothe at least one processor 410. The sidelink manager 470 may be ahardware, software, or firmware component that, when executed, causesthe UE 400 to perform the operations described herein. For example, thesidelink manager 470 may be a software module stored in memory 414 andexecutable by the at least one processor 410. As another example, thesidelink manager 470 may be a hardware circuit (e.g., an ASIC, afield-programmable gate array (FPGA), etc.) within the UE 400.

FIG. 5 illustrates an example of a wireless communications system 500that supports wireless unicast sidelink establishment, according toaspects of the disclosure. In some examples, wireless communicationssystem 500 may implement aspects of wireless communications systems 100,200, and 250. Wireless communications system 500 may include a first UE502 and a second UE 504, which may be examples of any of the UEsdescribed herein. As specific examples, UEs 502 and 504 may correspondto V-UEs 160 in FIG. 1 , UE 190 and UE 104 in FIG. 1 connected over D2DP2P link 192, or UEs 204 in FIGS. 2A and 2B.

In the example of FIG. 5 , the UE 502 may attempt to establish a unicastconnection over a sidelink with the UE 504, which may be a V2X sidelinkbetween the UE 502 and UE 504. As specific examples, the establishedsidelink connection may correspond to sidelinks 162 and/or 168 in FIG. 1. The sidelink connection may be established in an omni-directionalfrequency range (e.g., FR1) and/or a mmW frequency range (e.g., FR2). Insome cases, the UE 502 may be referred to as an initiating UE thatinitiates the sidelink connection procedure, and the UE 504 may bereferred to as a target UE that is targeted for the sidelink connectionprocedure by the initiating UE.

For establishing the unicast connection, access stratum (AS) (afunctional layer in the UMTS and LTE protocol stacks between the RAN andthe UE that is responsible for transporting data over wireless links andmanaging radio resources, and which is part of Layer 2) parameters maybe configured and negotiated between the UE 502 and UE 504. For example,a transmission and reception capability matching may be negotiatedbetween the UE 502 and UE 504. Each UE may have different capabilities(e.g., transmission and reception, 64 quadrature amplitude modulation(QAM), transmission diversity, carrier aggregation (CA), supportedcommunications frequency band(s), etc.). In some cases, differentservices may be supported at the upper layers of corresponding protocolstacks for UE 502 and UE 504. Additionally, a security association maybe established between UE 502 and UE 504 for the unicast connection.Unicast traffic may benefit from security protection at a link level(e.g., integrity protection). Security requirements may differ fordifferent wireless communications systems. For example, V2X and Uusystems may have different security requirements (e.g., Uu security doesnot include confidentiality protection). Additionally, IP configurations(e.g., IP versions, addresses, etc.) may be negotiated for the unicastconnection between UE 502 and UE 504.

In some cases, UE 504 may create a service announcement (e.g., a servicecapability message) to transmit over a cellular network (e.g., cV2X) toassist the sidelink connection establishment. Conventionally, UE 502 mayidentify and locate candidates for sidelink communications based on abasic service message (BSM) broadcasted unencrypted by nearby UEs (e.g.,UE 504). The BSM may include location information, security and identityinformation, and vehicle information (e.g., speed, maneuver, size, etc.)for the corresponding UE. However, for different wireless communicationssystems (e.g., D2D or V2X communications), a discovery channel may notbe configured so that UE 502 is able to detect the BSM(s). Accordingly,the service announcement transmitted by UE 504 and other nearby UEs(e.g., a discovery signal) may be an upper layer signal and broadcasted(e.g., in an NR sidelink broadcast). In some cases, the UE 504 mayinclude one or more parameters for itself in the service announcement,including connection parameters and/or capabilities it possesses. The UE502 may then monitor for and receive the broadcasted serviceannouncement to identify potential UEs for corresponding sidelinkconnections. In some cases, the UE 502 may identify the potential UEsbased on the capabilities each UE indicates in their respective serviceannouncements.

The service announcement may include information to assist the UE 502(e.g., or any initiating UE) to identify the UE transmitting the serviceannouncement (UE 504 in the example of FIG. 5 ). For example, theservice announcement may include channel information where directcommunication requests may be sent. In some cases, the channelinformation may be RAT-specific (e.g., specific to LTE or NR) and mayinclude a resource pool within which UE 502 transmits the communicationrequest. Additionally, the service announcement may include a specificdestination address for the UE (e.g., a Layer 2 destination address) ifthe destination address is different from the current address (e.g., theaddress of the streaming provider or UE transmitting the serviceannouncement). The service announcement may also include a network ortransport layer for the UE 502 to transmit a communication request on.For example, the network layer (also referred to as “Layer 3” or “L3”)or the transport layer (also referred to as “Layer 4” or “L4”) mayindicate a port number of an application for the UE transmitting theservice announcement. In some cases, no IP addressing may be needed ifthe signaling (e.g., PC5 signaling) carries a protocol (e.g., areal-time transport protocol (RTP)) directly or gives alocally-generated random protocol. Additionally, the serviceannouncement may include a type of protocol for credential establishmentand QoS-related parameters.

After identifying a potential sidelink connection target (UE 504 in theexample of FIG. 5 ), the initiating UE (UE 502 in the example of FIG. 5) may transmit a connection request 515 to the identified target UE 504.In some cases, the connection request 515 may be a first RRC messagetransmitted by the UE 502 to request a unicast connection with the UE504 (e.g., an “RRCDirectConnectionSetupRequest” message). For example,the unicast connection may utilize the PC5 interface for the sidelink,and the connection request 515 may be an RRC connection setup requestmessage. Additionally, the UE 502 may use a sidelink signaling radiobearer 505 to transport the connection request 515.

After receiving the connection request 515, the UE 504 may determinewhether to accept or reject the connection request 515. The UE 504 maybase this determination on a transmission/reception capability, anability to accommodate the unicast connection over the sidelink, aparticular service indicated for the unicast connection, the contents tobe transmitted over the unicast connection, or a combination thereof.For example, if the UE 502 wants to use a first RAT to transmit orreceive data, but the UE 504 does not support the first RAT, then the UE504 may reject the connection request 515. Additionally oralternatively, the UE 504 may reject the connection request 515 based onbeing unable to accommodate the unicast connection over the sidelink dueto limited radio resources, a scheduling issue, etc. Accordingly, the UE504 may transmit an indication of whether the request is accepted orrejected in a connection response 520. Similar to the UE 502 and theconnection request 515, the UE 504 may use a sidelink signaling radiobearer 510 to transport the connection response 520. Additionally, theconnection response 520 may be a second RRC message transmitted by theUE 504 in response to the connection request 515 (e.g., an“RRCDirectConnectionResponse” message).

In some cases, sidelink signaling radio bearers 505 and 510 may be thesame sidelink signaling radio bearer or may be separate sidelinksignaling radio bearers. Accordingly, a radio link control (RLC) layeracknowledged mode (AM) may be used for sidelink signaling radio bearers505 and 510. A UE that supports the unicast connection may listen on alogical channel associated with the sidelink signaling radio bearers. Insome cases, the AS layer (i.e., Layer 2) may pass information directlythrough RRC signaling (e.g., control plane) instead of a V2X layer(e.g., data plane).

If the connection response 520 indicates that the UE 504 accepted theconnection request 515, the UE 502 may then transmit a connectionestablishment 525 message on the sidelink signaling radio bearer 505 toindicate that the unicast connection setup is complete. In some cases,the connection establishment 525 may be a third RRC message (e.g., an“RRCDirectConnectionSetupComplete” message). Each of the connectionrequest 515, the connection response 520, and the connectionestablishment 525 may use a basic capability when being transported fromone UE to the other UE to enable each UE to be able to receive anddecode the corresponding transmission (e.g., the RRC messages).

Additionally, identifiers may be used for each of the connection request515, the connection response 520, and the connection establishment 525.For example, the identifiers may indicate which UE 502/504 istransmitting which message and/or for which UE 502/504 the message isintended. For physical (PHY) layer channels, the RRC signaling and anysubsequent data transmissions may use the same identifier (e.g., Layer 2IDs). However, for logical channels, the identifiers may be separate forthe RRC signaling and for the data transmissions. For example, on thelogical channels, the RRC signaling and the data transmissions may betreated differently and have different acknowledgement (ACK) feedbackmessaging. In some cases, for the RRC messaging, a physical layer ACKmay be used for ensuring the corresponding messages are transmitted andreceived properly.

One or more information elements may be included in the connectionrequest 515 and/or the connection response 520 for UE 502 and/or UE 504,respectively, to enable negotiation of corresponding AS layer parametersfor the unicast connection. For example, the UE 502 and/or UE 504 mayinclude packet data convergence protocol (PDCP) parameters in acorresponding unicast connection setup message to set a PDCP context forthe unicast connection. In some cases, the PDCP context may indicatewhether or not PDCP duplication is utilized for the unicast connection.Additionally, the UE 502 and/or UE 504 may include RLC parameters whenestablishing the unicast connection to set an RLC context for theunicast connection. For example, the RLC context may indicate whether anAM (e.g., a reordering timer (t-reordering) is used) or anunacknowledged mode (UM) is used for the RLC layer of the unicastcommunications.

Additionally, the UE 502 and/or UE 504 may include medium access control(MAC) parameters to set a MAC context for the unicast connection. Insome cases, the MAC context may enable resource selection algorithms, ahybrid automatic repeat request (HARQ) feedback scheme (e.g., ACK ornegative ACK (NACK) feedback), parameters for the HARQ feedback scheme,carrier aggregation, or a combination thereof for the unicastconnection. Additionally, the UE 502 and/or UE 504 may include PHY layerparameters when establishing the unicast connection to set a PHY layercontext for the unicast connection. For example, the PHY layer contextmay indicate a transmission format (unless transmission profiles areincluded for each UE 502/504) and a radio resource configuration (e.g.,bandwidth part (BWP), numerology, etc.) for the unicast connection.These information elements may be supported for different frequencyrange configurations (e.g., FR1 and FR2).

In some cases, a security context may also be set for the unicastconnection (e.g., after the connection establishment 525 message istransmitted). Before a security association (e.g., security context) isestablished between the UE 502 and UE 504, the sidelink signaling radiobearers 505 and 510 may not be protected. After a security associationis established, the sidelink signaling radio bearers 505 and 510 may beprotected. Accordingly, the security context may enable secure datatransmissions over the unicast connection and the sidelink signalingradio bearers 505 and 510. Additionally, IP layer parameters (e.g.,link-local IPv4 or IPv6 addresses) may also be negotiated. In somecases, the IP layer parameters may be negotiated by an upper layercontrol protocol running after RRC signaling is established (e.g., theunicast connection is established). As noted above, the UE 504 may baseits decision on whether to accept or reject the connection request 515on a particular service indicated for the unicast connection and/or thecontents to be transmitted over the unicast connection (e.g., upperlayer information). The particular service and/or contents may be alsoindicated by an upper layer control protocol running after RRC signalingis established.

After the unicast connection is established, the UE 502 and UE 504 maycommunicate using the unicast connection over a sidelink 530, wheresidelink data 535 is transmitted between the two UEs 502 and 504. Thesidelink 530 may correspond to sidelinks 162 and/or 168 in FIG. 1 . Insome cases, the sidelink data 535 may include RRC messages transmittedbetween the two UEs 502 and 504. To maintain this unicast connection onsidelink 530, UE 502 and/or UE 504 may transmit a keep alive message(e.g., “RRCDirectLinkAlive” message, a fourth RRC message, etc.). Insome cases, the keep alive message may be triggered periodically oron-demand (e.g., event-triggered). Accordingly, the triggering andtransmission of the keep alive message may be invoked by UE 502 or byboth UE 502 and UE 504. Additionally or alternatively, a MAC controlelement (CE) (e.g., defined over sidelink 530) may be used to monitorthe status of the unicast connection on sidelink 530 and maintain theconnection. When the unicast connection is no longer needed (e.g., UE502 travels far enough away from UE 504), either UE 502 and/or UE 504may start a release procedure to drop the unicast connection oversidelink 530. Accordingly, subsequent RRC messages may not betransmitted between UE 502 and UE 504 on the unicast connection.

Various physical sidelink channels can be used for sidelinkcommunication and/or RF-EH, including Physical sidelink control channel(PSCCH), Physical sidelink shared channel (PSSCH), Physical sidelinkfeedback channel (PSFCH), and Physical sidelink broadcast channel(PSBCH). Various sidelink reference signals can be used for sidelinkcommunication and/or RF-EH, including Demodulation RS (DMRS) for PSCCH,Demodulation RS (DMRS) for PSSCH, Demodulation RS (DMRS) for PSBCH,Channel state information RS (CSI-RS), Primary synchronization signal(S-PSS), Secondary synchronization signal (S-SSS), and Phase-tracking RS(PTRS) for FR2 only.

In some designs, a slot may include 14 OFDM symbols including resourcearranged in accordance with a time division duplex (TDD) resourceconfiguration. In some designs, sidelink can be configured (e.g.,pre-configured or dynamically configured) to occupy fewer than 14symbols in a slot. In some designs, the first symbol is repeated on thepreceding symbol for automatic gain control (AGC) settling. In somedesigns, the sub-channel size can be configured (e.g., pre-configured ordynamically configured) to {10, 15, 20, 25, 50, 75, 100} physicalresource blocks (PRBs). In some designs, the PSCCH and PSSCH are alwaystransmitted in the same slot.

In some designs, to receive a sidelink packet, a UE performs a blindsearch in all sidelink sub-channels. The number of subchannel istypically small, e.g., 1-27 subchannels, so that blind searching allsubchannels still feasible. In some designs, PSSCH can occupy up toN_(subchannel) ^(SL), contiguous subchannels. In some designs, PSCCH canoccupy up to one subchannel with the lowest subchannel index. In somedesigns, a 1^(st) stage SCI is transmitted in PSCCH containinginformation about PSSCH bandwidth and resource reservations in futureslots. In some designs, a 2^(nd) stage SCI can be found and decodedafter decoding PSCCH, source ID and destination ID are used todistinguish whether the packet is for the UE and coming from which UE.In some designs, the subchannel size in V2X may be large, e.g., minimum10 RBs. In some designs, cellular (C-V2X) intends the UEs to decode alltransmissions and requires blind searching of all subchannels.

FIG. 6A illustrates one example of a TDD sidelink (PC5) resourceconfiguration 600 in accordance with an aspect of the disclosure. TheTDD sidelink (PC5) resource configuration 600 may include 14 OFDMsymbols denoted as symbols 0 through 13. In the TDD sidelink (PC5)resource configuration 600 of FIG. 6A, PSCCH is allocated to symbols 0-3(e.g., in a first bandwidth), PSSCH is allocated to symbols 0-3 (e.g.,in a second bandwidth) and to symbols 4-9, a gap is defined in symbol10, PSFCH is allocated to symbols 11-12, and a gap is defined in symbol13. The TDD sidelink (PC5) resource configuration 600 is only oneexample resource configuration, and other configurations are possible inother aspects.

Referring to FIG. 6A, with respect to SCI 1_0 in PSCCH, a frequencydomain resource allocation (FDRA) may be configured with

$\left\lceil {\log\frac{N_{subchannel}^{SL}\left( {N_{subchannel}^{SL} + 1} \right)}{2}} \right\rceil$

bits for 2 reservations, or

$\left\lceil {\log\frac{{N_{subchannel}^{SL}\left( {N_{subchannel}^{SL} + 1} \right)}\left( {{2N_{subchannel}^{SL}} + 1} \right)}{6}} \right\rceil$

bits for 3 reservations, and a time domain resource allocation (TDRA)may be configured with 5 bits for 2 reservations or 9 bits for 3reservations.

FIG. 6B illustrates an SCI-based resource reservation scheme 650 inaccordance with an aspect of the disclosure. In FIG. 6B, a firstreservation 652 is defined at slot i, a second reservation 654 is offsetfrom slot i by x slots (slot i+x) where 0<x≤31, and a third reservation656 is offset from slot I by y slots (slot i+y) where x<y≤31.

Referring to FIGS. 6A-6B, in some designs, PSCCH is (pre)configured tooccupy {10, 12, 15, 20, 25} PRBs, limited to a single sub-channel. Insome designs, PSCCH duration is (pre)configured to 2 or 3 symbols. Insome designs, a sub-channel can occupy {10, 15, 20, 25, 50, 75, 100}PRBs. In some designs, a number of subchannels can be 1-27 in a resourcepool (RP). In some designs, PSCCH size is fixed for a resource pool(e.g., PSCCCH size may occupy 10% to 100% of one subchannel (first 2 or3 symbols), depending on configuration). In some designs, PSSCH occupiesat least 1 subchannel and contains 2^(nd) stage SCI.

NR supports a number of cellular network-based positioning technologies,including downlink-based, uplink-based, and downlink-and-uplink-basedpositioning methods. Downlink-based positioning methods include observedtime difference of arrival (OTDOA) in LTE, downlink time difference ofarrival (DL-TDOA) in NR, and downlink angle-of-departure (DL-AoD) in NR.FIG. 7 illustrates examples of various positioning methods, according toaspects of the disclosure. In an OTDOA or DL-TDOA positioning procedure,illustrated by scenario 710, a UE measures the differences between thetimes of arrival (ToAs) of reference signals (e.g., positioningreference signals (PRS)) received from pairs of base stations, referredto as reference signal time difference (RSTD) or time difference ofarrival (TDOA) measurements, and reports them to a positioning entity.More specifically, the UE receives the identifiers (IDs) of a referencebase station (e.g., a serving base station) and multiple non-referencebase stations in assistance data. The UE then measures the RSTD betweenthe reference base station and each of the non-reference base stations.Based on the known locations of the involved base stations and the RSTDmeasurements, the positioning entity can estimate the UE's location.

For DL-AoD positioning, illustrated by scenario 720, the positioningentity uses a beam report from the UE of received signal strengthmeasurements of multiple downlink transmit beams to determine theangle(s) between the UE and the transmitting base station(s). Thepositioning entity can then estimate the location of the UE based on thedetermined angle(s) and the known location(s) of the transmitting basestation(s).

Uplink-based positioning methods include uplink time difference ofarrival (UL-TDOA) and uplink angle-of-arrival (UL-AoA). UL-TDOA issimilar to DL-TDOA, but is based on uplink reference signals (e.g.,sounding reference signals (SRS)) transmitted by the UE. For UL-AoApositioning, one or more base stations measure the received signalstrength of one or more uplink reference signals (e.g., SRS) receivedfrom a UE on one or more uplink receive beams. The positioning entityuses the signal strength measurements and the angle(s) of the receivebeam(s) to determine the angle(s) between the UE and the basestation(s). Based on the determined angle(s) and the known location(s)of the base station(s), the positioning entity can then estimate thelocation of the UE.

Downlink-and-uplink-based positioning methods include enhanced cell-ID(E-CID) positioning and multi-round-trip-time (RTT) positioning (alsoreferred to as “multi-cell RTT”). In an RTT procedure, an initiator (abase station or a UE) transmits an RTT measurement signal (e.g., a PRSor SRS) to a responder (a UE or base station), which transmits an RTTresponse signal (e.g., an SRS or PRS) back to the initiator. The RTTresponse signal includes the difference between the ToA of the RTTmeasurement signal and the transmission time of the RTT response signal,referred to as the reception-to-transmission (Rx-Tx) time difference.The initiator calculates the difference between the transmission time ofthe RTT measurement signal and the ToA of the RTT response signal,referred to as the transmission-to-reception (Tx-Rx) time difference.The propagation time (also referred to as the “time of flight”) betweenthe initiator and the responder can be calculated from the Tx-Rx andRx-Tx time differences. Based on the propagation time and the knownspeed of light, the distance between the initiator and the responder canbe determined. For multi-RTT positioning, illustrated by scenario 730, aUE performs an RTT procedure with multiple base stations to enable itslocation to be determined (e.g., using multilateration) based on theknown locations of the base stations. RTT and multi-RTT methods can becombined with other positioning techniques, such as UL-AoA, illustratedby scenario 740, and DL-AoD, to improve location accuracy.

The E-CID positioning method is based on radio resource management (RRM)measurements. In E-CID, the UE reports the serving cell ID, the timingadvance (TA), and the identifiers, estimated timing, and signal strengthof detected neighbor base stations. The location of the UE is thenestimated based on this information and the known locations of the basestation(s).

To assist positioning operations, a location server (e.g., locationserver 230, LMF 270, SLP 272) may provide assistance data to the UE. Forexample, the assistance data may include identifiers of the basestations (or the cells/TRPs of the base stations) from which to measurereference signals, the reference signal configuration parameters (e.g.,the number of consecutive positioning subframes, periodicity ofpositioning subframes, muting sequence, frequency hopping sequence,reference signal identifier, reference signal bandwidth, etc.), and/orother parameters applicable to the particular positioning method.Alternatively, the assistance data may originate directly from the basestations themselves (e.g., in periodically broadcasted overheadmessages, etc.). In some cases, the UE may be able to detect neighbornetwork nodes itself without the use of assistance data.

In the case of an OTDOA or DL-TDOA positioning procedure, the assistancedata may further include an expected RSTD value and an associateduncertainty, or search window, around the expected RSTD. In some cases,the value range of the expected RSTD may be +/−500 microseconds (μs). Insome cases, when any of the resources used for the positioningmeasurement are in FR1, the value range for the uncertainty of theexpected RSTD may be +/−32 μs. In other cases, when all of the resourcesused for the positioning measurement(s) are in FR2, the value range forthe uncertainty of the expected RSTD may be +/−8 μs.

A location estimate may be referred to by other names, such as aposition estimate, location, position, position fix, fix, or the like. Alocation estimate may be geodetic and comprise coordinates (e.g.,latitude, longitude, and possibly altitude) or may be civic and comprisea street address, postal address, or some other verbal description of alocation. A location estimate may further be defined relative to someother known location or defined in absolute terms (e.g., using latitude,longitude, and possibly altitude). A location estimate may include anexpected error or uncertainty (e.g., by including an area or volumewithin which the location is expected to be included with some specifiedor default level of confidence).

FIG. 8 illustrates sidelink communication scheduling (or resourceallocation) schemes 800 in accordance with aspects of the disclosure. Insome designs, resource allocation in V2X may be implemented via Mode 1,where gNB assigns Tx resources for sidelink communications through DCI3_0. In other designs, resource allocation in V2X may be implemented viaMode 2, where a transmitting UE autonomously decides resources forsidelink communications. In some designs, the receiving UE behavior isthe same for both Modes 1 and 2.

Referring to FIG. 8 , Mode 1 supports dynamic grants (DG), configuredgrants (CG) type 1, and CG type 2. In some designs, CG type 1 isactivated via RRC signaling from gNB. DCI 3_0 is transmitted by gNB toallocation time and frequency resources and indicates transmissiontiming. In some designs, the modulation and coding scheme (MCS) MCS isup to UE within limit set by gNB. In Mode 2, the transmitting UEperforms channel sensing by blindly decoding all PSCCH channels andfinds out reserved resources by other sidelink transmissions. Thetransmitting UE reports available resources to upper layer and upperlayer decides resource usage.

In some designs, in industrial IoT (IIoT), sidelink can enable directprogrammable logical controller (PLC) and sensors/actuators (SAs)communications. Wireless PLC is desired for flexible and simpledeployment. In some designs, each PLC controls 20-50 SAs. In somedesigns, IIoT has low latency 1˜2 ms and ultra-reliability requirement10⁻⁶ error rate. In some designs, communication through gNB wouldrequire multiple OTAs, affecting latency and reliability.

IIoT traffics are typically deterministic and with small packet size32-256 bytes. The required bandwidth is thus low, e.g., 2 RBs might besufficient for some cases. SAs may have constraint on UE capability interms of bandwidth and processing power. Overall bandwidth may be largefor IIoT with dedicated frequency bands and/or unlicensed bands. In somedesigns, SAs need not detect/monitor all transmissions. In some designs,PSCCH has to meet stringent IIoT requirement. IIoT networks may also beassociated with challenging RF environments due to blockage andinterference.

As noted above, a 1^(st) stage SCI may be included in PSCCH. The 1^(st)stage SCI may alternatively be referred to as SCI 1-A. In some designs,SCI 1-A shall be decoded by intended RXs and other sidelink UEs(particularly in Mode 2) to allow channel sensing and avoid resourcecollision. In some designs, SCI 1-A may be configured as follows:

-   -   Priority 3 bits    -   Frequency resource assignment, bits depending on # of slot        reservations and #subchannels    -   Time resource assignment, 5 or 9 bits for 2 or 3 reservations    -   Resource reservation period, bits depending on # allowed periods    -   DM-RS pattern, bits depending on # configured patterns    -   SCI 2 format, 2 bits    -   Beta offset for SCI 2 rate matching, 2 bits    -   DM-RS port, 1 bit indicating one or two data layers    -   MCS, 5 bits    -   Additional MCS table, 0-2 bits    -   PSFCH overhead indicator, 0 or 1 bit    -   Reserved bits, bits up to upper layer

As noted above, a 2^(nd) stage SCI may be included in PSSCH. The 2^(nd)stage SCI may alternatively be referred to as SCI 2. In some designs,SCI 2 is intended to help receiving UEs decode the PSSCH. In somedesigns, SCI 2 may be configured as follows:

-   -   HARQ ID, bits depending on # HARQ process    -   NDI, 1 bit    -   RV-ID, 2 bits    -   Source ID, 8 bits    -   Dest. ID, 16 bits    -   HARQ enable/disable, 1 bit    -   SCI 2-A only fields: Cast type, 2 bits, broadcast, groupcast,        unicast; CSI request, 1 bit    -   SCI 2-B only fields (NACK-only groupcast): Zone ID, 12 bits;        Communication range, 4 bits

In addition to the downlink-based, uplink-based, anddownlink-and-uplink-based positioning methods, NR supports varioussidelink positioning techniques. For example, link-level ranging signalscan be used to estimate the distance between pairs of V-UEs or between aV-UE and a roadside unit (RSU), similar to a round-trip-time (RTT)positioning procedure.

FIG. 9 illustrates an example wireless communication system 900 in whicha V-UE 904 is exchanging ranging signals with an RSU 910 and anotherV-UE 906, according to aspects of the disclosure. As illustrated in FIG.9 , a wideband (e.g., FR1) ranging signal (e.g., a Zadoff Chu sequence)is transmitted by both end points (e.g., V-UE 904 and RSU 910 and V-UE904 and V-UE 906). In an aspect, the ranging signals may be sidelinkpositioning reference signals (SL-PRS) transmitted by the involved V-UEs904 and 906 on uplink resources. On receiving a ranging signal from atransmitter (e.g., V-UE 904), the receiver (e.g., RSU 910 and/or V-UE906) responds by sending a ranging signal that includes a measurement ofthe difference between the reception time of the ranging signal and thetransmission time of the response ranging signal, referred to as thereception-to-transmission (Rx-Tx) time difference measurement of thereceiver.

Upon receiving the response ranging signal, the transmitter (or otherpositioning entity) can calculate the RTT between the transmitter andthe receiver based on the receiver's Rx-Tx time difference measurementand a measurement of the difference between the transmission time of thefirst ranging signal and the reception time of the response rangingsignal (referred to as the transmission-to-reception (Tx-Rx) timedifference measurement of the transmitter). The transmitter (or otherpositioning entity) uses the RTT and the speed of light to estimate thedistance between the transmitter and the receiver. If one or both of thetransmitter and receiver are capable of beamforming, the angle betweenthe V-UEs 904 and 906 may also be able to be determined. In addition, ifthe receiver provides its global positioning system (GPS) location inthe response ranging signal, the transmitter (or other positioningentity) may be able to determine an absolute location of thetransmitter, as opposed to a relative location of the transmitter withrespect to the receiver.

As will be appreciated, ranging accuracy improves with the bandwidth ofthe ranging signals. Specifically, a higher bandwidth can betterseparate the different multipaths of the ranging signals.

Note that this positioning procedure assumes that the involved V-UEs aretime-synchronized (i.e., their system frame time is the same as, or hasa known offset relative to, the other V-UE(s)). In addition, althoughFIG. 9 illustrates two V-UEs, as will be appreciated, they need not beV-UEs, and may instead be any other type of UE capable of sidelinkcommunication.

FIG. 10 illustrates other sidelink positioning schemes 1000 inaccordance with aspects of the disclosure. In FIG. 10 , each positioningscheme involves a target UE (in this case, a VR headset), at least onegNB, and at least one reference UE (e.g., a UE with a known locationfrom a recent positioning fix, where such a location generally has alower variance than a typical error estimate for UE position).

Referring to FIG. 10 , scenario 1010 depicts a UE with a known locationimproving Uu positioning (e.g., RTT-based or TDOA-based) by providing anextra anchor. Scenario 1020 depicts positioning for a low-tier UE (e.g.,VR headset) via the help from premium UEs (i.e., SL-only basedpositioning/ranging). Scenario 1030 depicts a relay or reference UE(with known location) participating in position estimation for a remoteUE (e.g., VR headset) without UL PRS transmission in Uu. Each of thescenarios 1010-1030 may be broadly characterized as an SL-assistedpositioning scheme.

The SL UEs that are assisting in position estimation of a target UE canimpact various aspects associated with SL-assisted positioning, such aspower consumption and/or position estimation accuracy.

FIG. 11 illustrates other UE distribution scenarios 1100 for sidelinkpositioning in accordance with aspects of the disclosure. In UEdistribution scenario 1110, a high number of UEs participate inSL-assisted positioning, which is good for position estimation accuracybut also greatly increases power consumption. In UE distributionscenario 1120, only two UEs participate in SL-assisted positioning,which is good for power consumption but also reduces position estimationaccuracy. In UE distribution scenario 1130, there is a reasonable number(i.e., 4) UEs participating in SL-assisted positioning, so the powerconsumption is not too high and the UEs are also well spaced apart witha sufficient number for good position estimation accuracy.

Aspects of the disclosure are directed to selection of UEs forparticipation in a sidelink-assisted position estimation procedure of atarget UE based at least in part upon zone information associated with agroup of candidate UEs. Such aspects may provide various technicaladvantages, such as improved position estimation accuracy and/or lowerpower consumption (e.g., across the various UEs involved with thesidelink-assisted position estimation procedure) by spreading thedistribution of participating UEs across zones.

FIG. 12 illustrates an exemplary process 1200 of wireless communication,according to aspects of the disclosure. In an aspect, the process 1200may be performed by a target UE (e.g., a UE for which positionestimation is desired), such as UE 302.

Referring to FIG. 12 , at 1210, the target UE (e.g., receiver 312 or322, etc.) receives zone information associated with a plurality ofzones, the zone information indicating, for each of a plurality ofcandidate UEs for a sidelink-assisted position estimation procedure ofthe target UE, a zone identifier of a zone in which the respectivecandidate UE is located. In some designs, the zone information for someor all of the plurality of candidate UEs is broadcasted by therespective candidate UE (e.g., in which case, the zone information for aparticular candidate UE is received directly from that particularcandidate UE). In some designs, the broadcasted zone information istransmitted via SCI of a PSCCH (e.g., a 1^(st) stage SCI, such as SCI1-A). In other designs, the zone information for some or all of theplurality of candidate UEs is received indirectly from a differentrespective UE (e.g., via a relaying or forwarding scheme across a meshnetwork of UEs) or from a base station (e.g., gNB accumulates zoneinformation for various UEs and then broadcasts the zone informationassociated with nearby zones). The zone information may include avariety of information, as will be described below in more detail. Insome designs, a means for performing the reception of the zoneinformation at 1210 may include receiver 312 or 322 of UE 302.

Referring to FIG. 12 , at 1220, the target UE (e.g., processor(s) 332,on-demand PRS component 342, etc.) selects one or more candidate UEs forthe sidelink-assisted position estimation procedure based at least inpart upon the zone information. In some designs, the selection of 1220may be based upon one or more zone-based rules, as will be describedbelow in more detail. In some designs, a means for performing theselection of the zone candidate UE(s) at 1220 may include processor(s)332, on-demand PRS component 342, etc. of UE 302.

Referring to FIG. 12 , at 1230, the target UE (e.g., processor(s) 332,transmitter 314 or 314, receiver 312 or 322, etc.) performs thesidelink-assisted position estimation procedure with at least theselected one or more candidate UEs. The sidelink-assisted positionestimation procedure can be performed in implemented in various ways(e.g., RTT, multi-RTT or differential RTT or double-differential RTT,TDOA-based, etc.). In some designs, each reference node associated withthe sidelink-assisted position estimation procedures corresponds to theselected one or more candidate UEs (e.g., as in SL-only RTT scheme 1030as one example). In other designs, at least one reference nodeassociated with the sidelink-assisted position estimation procedurescorresponds to a base station (e.g., a hybrid sidelink/gNB positioningscheme, such as 1010 or 1020 of FIG. 10 , etc.). In some designs, ameans for performing the sidelink-assisted position estimation procedureat 1230 may include processor(s) 332, transmitter 314 or 314, receiver312 or 322, etc. of UE 302, dependent on whether the target UE istransmitting SRS and/or measuring PRS and/or deriving Tx->Rxmeasurement, or whether the target UE is the position estimation entity(e.g., UE-based position estimation) or whether another UE or a networkcomponent (e.g., LMF) is the position estimation entity).

Referring to FIG. 12 , in some designs, the zone information furtherincludes an indication of accuracy for at least one zone identifierindications, and the selection at 1220 is further based on theindication of accuracy. In some designs, the indication of accuracy isindicated implicitly by the zone identifier (e.g., a zone ID associatedwith a known high-interference area may be, by default, associated witha low accuracy level). In other designs, the indication of accuracy isincluded in SCI of PSCCH (e.g., SCI 1-A) or PSSCH (e.g., SCI 2). In thiscase, the indication of accuracy may be based on dynamic conditions(e.g., if candidate UE is very close to boundary to another zone and/oris on a trajectory towards another zone, then the candidate UE mayindicate low accuracy to indicate a looser associated with the indicatedzone, etc.).

Referring to FIG. 12 , in some designs, a mapping of zone identifiers tozones or instructions on how to derive the mapping are pre-defined,pre-configured (e.g., via RRC or SIB), or received at the target UE froman external entity (e.g., via gNB or another UE). In some designs, thezone identifiers and their associated zones may be application-driven,or based on group communication services (GCS) protocol or locationservices (LCS) protocol. For example, for an indoor factory, a zone IDmay be associated with a particular hallway, etc. In some designs, zoneidentifier and associated zone computation may be implemented at theapplication-layer (e.g., derived independently at each UE, etc.).

Referring to FIG. 12 , in some designs, the selection is based upon oneor more zone-based rules. In some designs, the one or more zone-basedrules include:

-   -   excluding, from selection, any candidate UE within a first        threshold distance to the target UE, or    -   excluding, from selection, any candidate UE in the same zone as        the target UE, or    -   excluding, from selection, any candidate UE that exceeds a        second threshold distance to the target UE, or    -   excluding, from selection, any candidate UE in any zone that        exceeds a third threshold distance to respective zone of the        target UE, or    -   limiting selection of candidate UEs in the same zone to less        than a first threshold number, or    -   limiting selection of candidate UEs in an adjacent zone to the        respective zone of the target UE to less than a second threshold        number, or    -   a combination thereof.

In some designs, some or all of the above-noted rules may be implementedselectively based on various criteria. For example, if thesidelink-assisted position estimation procedure is based on timingmeasurements, then the exclusion of candidate UEs that are too close tothe target UE may be implemented (e.g., inside same zone or within firstthreshold distance). However, these nearby candidate UEs may be helpfulfor other types of position estimation that rely on angle-basedmeasurements (e.g., AoD or AoA). In this case, the proximity exclusioncan be implemented selectively based on the type of positioning scheme(e.g., timing-based or angle-based).

Referring to FIG. 12 , in some designs, the target UE may furtherdetermine a RSRP of at least one signal from at least one of theplurality of candidate UEs, the selection at 1220 is further based onthe RSRP determination (e.g., so zone information is considered, whileRSRP is also considered). Hence, the selection at 1220 need not be basedsolely on the zone information.

Referring to FIG. 12 , in some designs, the target UE may furtherdetermine a line of sight (LOS) or non-LOS (NLOS) confidence levelassociated with at least one link to at least one of the plurality ofcandidate UEs, and the selection at 1220 is further based on the LOS orNLOS confidence level determination (e.g., so zone information isconsidered, while LOS/NLOS condition is also considered). For example,candidate UEs with LOS links to the target UE may generally bepreferable for selection over candidate UEs with NLOS links to thetarget UE. Hence, the selection at 1220 need not be based solely on thezone information.

Referring to FIG. 12 , as noted above, the sidelink-assisted positionestimation procedure may include a timing measurement procedure (e.g.,RU or multi-RT or differential RU or double-differential RU or TDOA,etc.), an angle measurement procedure (e.g., AoA or AoD, etc.), or acombination thereof.

FIG. 13 illustrates an example implementation 1300 of the process 1200of FIG. 12 in accordance with an aspect of the disclosure. In FIG. 13 ,a grid is depicted whereby each box of the grid corresponds to aparticular zone associated with a respective zone identifier. Circlesare depicted in the grid which are marked to indicate the target UE, theselected candidate UEs, and the non-selected candidate UEs. As shown inFIG. 13 , the selected candidate UEs are spaced apart in terms of zonesand are angularly spaced apart as well to obtain a reasonable spatialdistribution of UEs for the sidelink-assisted position estimationprocedure.

FIG. 14 illustrates an example implementation 1400 of the process 1200of FIG. 12 in accordance with an aspect of the disclosure. FIG. 14 issimilar to FIG. 13 , except that a candidate UE cluster is depicted at1402 with a high number of nearby zone co-located UEs. In some designs,assisting UE in same/similar location (e.g., as in the candidate UEcluster 1402) may provide limited gain (e.g., hence the rationale tospace apart the selected candidate UEs). In some designs, one or fewassisting UE from same or adjacent zones may be sufficient for thesidelink-assisted position estimation procedure. In some designs, in ascenario where there are multiple candidate UEs available for selection,RSRP may be considered as a secondary factor (as described above), e.g.,based on based RSRP from SCI-1/SCI-2 and PSSCH. In some designs, asnoted above, “POS-Accuracy” information of candidate UEs may beconsidered by the target UE, including sync error info. In some designs,as noted above, the selection at 1220 may further based on expectation(or confidence level) of LOS/NLOS (e.g., derivable from DMRS or otherassistance information).

FIG. 15 illustrates an example implementation 1500 of the process 1200of FIG. 12 in accordance with an aspect of the disclosure. FIG. 15 issimilar to FIG. 13 , except that an proximity-based exclusion area isdepicted at 1502. In some designs, ToA for PRS between close-by UEs maybe sub 10 ns. In some designs, PRS and hardware bandwidth may not“resolve” ToA below a threshold. For example, a resolvable time betweensamples may be 1/SamplingFreq, or 3 m for 100 Mhz sampling rate. In somedesigns, sync error and other bias may cause error above a distancebetween UEs. In some designs, for timing-based positioning schemes,nearby UEs may only useful if close-by UE has very good POS accuracy. Insome designs, for nearby UEs, sharing POS-info via SL may be better thanreceiving PRS (e.g., instead of measuring PRS, simply identify a nearbyUE location to gain knowledge that the target UE is very close to thatlocation). As noted above, nearby UEs may be useful for other types ofposition estimation schemes, such as angle-based position estimationschemes.

FIG. 16 illustrates an example implementation 1600 of the process 1200of FIG. 12 in accordance with an aspect of the disclosure. FIG. 16 issimilar to FIG. 13 , except that an distance-based exclusion area isdepicted at 1602 with a number of “far” UEs. In some designs, PRS fromfarther away UE requires higher power consumption from both Tx and Rx.Accordingly, UEs inside the distance-based exclusion area 1602 may onlybe considered in scenarios where closer candidate UEs are not availablefor selection.

As noted above, geographic regions may be divided into multiple zones(alternatively referred to as sidelink zones or SL zones). In somedesigns, SL zones may be designed primarily for V2X implementations inoutdoor spaces (e.g., zones may encompass roads, parking lots, etc.,where vehicles travel, etc.).

FIG. 17 illustrates a zone 1700 in accordance with a World GeodeticSystem 84 (WSG84) model based on reference longitude and latitudecoordinates (0,0) in accordance with an aspect of the disclosure. Withrespect to FIG. 17 , in an example:

-   -   (x,y) is the distance to (0,0) in meters,    -   x1=floor(x/L) mode 64,    -   y1=floor(y/L) mode 64,    -   Zone_ID=y1*64+x1,    -   L is the length of the zone defined in sl-ZoneConfig

In this manner, the zone dimensions may be indicated via the zoneidentifier (or Zone_ID). A UE 1702 is shown as located inside of thezone 1700.

In current designs, SL zones are defined with reference to a globalgeographic coordinate (latitude and longitude). In particular, the (0,0)coordinate is a global geographic coordinate (e.g., based on GNSS, etc.)which is typically pre-defined in the relevant standard. In otherdesigns, the reference geographic coordinate may be more flexiblydefined (e.g., a local reference geographic coordinate can be defined,or even a global reference geographic coordinate that may be differentfrom the predefined reference global geographic coordinate used inlegacy systems).

A collection of resource elements (REs) that are used for transmissionof PRS is referred to as a “PRS resource.” The collection of resourceelements can span multiple PRBs in the frequency domain and ‘N’ (such as1 or more) consecutive symbol(s) within a slot in the time domain. In agiven OFDM symbol in the time domain, a PRS resource occupiesconsecutive PRBs in the frequency domain.

The transmission of a PRS resource within a given PRB has a particularcomb size (also referred to as the “comb density”). A comb size ‘N’represents the subcarrier spacing (or frequency/tone spacing) withineach symbol of a PRS resource configuration. Specifically, for a combsize ‘N,’ PRS are transmitted in every Nth subcarrier of a symbol of aPRB. For example, for comb-4, for each symbol of the PRS resourceconfiguration, REs corresponding to every fourth subcarrier (such assubcarriers 0, 4, 8) are used to transmit PRS of the PRS resource.Currently, comb sizes of comb-2, comb-4, comb-6, and comb-12 aresupported for DL-PRS.

Currently, a DL-PRS resource may span 2, 4, 6, or 12 consecutive symbolswithin a slot with a fully frequency-domain staggered pattern. A DL-PRSresource can be configured in any higher layer configured downlink orflexible (FL) symbol of a slot. There may be a constant energy perresource element (EPRE) for all REs of a given DL-PRS resource. Thefollowing are the frequency offsets from symbol to symbol for comb sizes2, 4, 6, and 12 over 2, 4, 6, and 12 symbols. 2-symbol comb-2: {0, 1};4-symbol comb-2: {0, 1, 0, 1}; 6-symbol comb-2: {0, 1, 0, 1, 0, 1};12-symbol comb-2: {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1}; 4-symbol comb-4:{0, 2, 1, 3} (as in the example of FIG. 4 ); 12-symbol comb-4: {0, 2, 1,3, 0, 2, 1, 3, 0, 2, 1, 3}; 6-symbol comb-6: {0, 3, 1, 4, 2, 5};12-symbol comb-6: {0, 3, 1, 4, 2, 5, 0, 3, 1, 4, 2, 5}; and 12-symbolcomb-12: {0, 6, 3, 9, 1, 7, 4, 10, 2, 8, 5, 11}.

A “PRS resource set” is a set of PRS resources used for the transmissionof PRS signals, where each PRS resource has a PRS resource ID. Inaddition, the PRS resources in a PRS resource set are associated withthe same TRP. A PRS resource set is identified by a PRS resource set IDand is associated with a particular TRP (identified by a TRP ID). Inaddition, the PRS resources in a PRS resource set have the sameperiodicity, a common muting pattern configuration, and the samerepetition factor (such as “PRS-ResourceRepetitionFactor”) across slots.The periodicity is the time from the first repetition of the first PRSresource of a first PRS instance to the same first repetition of thesame first PRS resource of the next PRS instance. The periodicity mayhave a length selected from 2{circumflex over ( )}μ*{4, 5, 8, 10, 16,20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, withμ=0, 1, 2, 3. The repetition factor may have a length selected from {1,2, 4, 6, 8, 16, 32} slots.

A PRS resource ID in a PRS resource set is associated with a single beam(or beam ID) transmitted from a single TRP (where a TRP may transmit oneor more beams). That is, each PRS resource of a PRS resource set may betransmitted on a different beam, and as such, a “PRS resource,” orsimply “resource,” also can be referred to as a “beam.” Note that thisdoes not have any implications on whether the TRPs and the beams onwhich PRS are transmitted are known to the UE.

A “PRS instance” or “PRS occasion” is one instance of a periodicallyrepeated time window (such as a group of one or more consecutive slots)where PRS are expected to be transmitted. A PRS occasion also may bereferred to as a “PRS positioning occasion,” a “PRS positioninginstance, a “positioning occasion,” “a positioning instance,” a“positioning repetition,” or simply an “occasion,” an “instance,” or a“repetition.”

A “positioning frequency layer” (also referred to simply as a “frequencylayer”) is a collection of one or more PRS resource sets across one ormore TRPs that have the same values for certain parameters.Specifically, the collection of PRS resource sets has the samesubcarrier spacing and cyclic prefix (CP) type (meaning all numerologiessupported for the physical downlink shared channel (PDSCH) are alsosupported for PRS), the same Point A, the same value of the downlink PRSbandwidth, the same start PRB (and center frequency), and the samecomb-size. The Point A parameter takes the value of the parameter“ARFCN-ValueNR” (where “ARFCN” stands for “absolute radio-frequencychannel number”) and is an identifier/code that specifies a pair ofphysical radio channel used for transmission and reception. The downlinkPRS bandwidth may have a granularity of four PRBs, with a minimum of 24PRBs and a maximum of 272 PRBs. Currently, up to four frequency layershave been defined, and up to two PRS resource sets may be configured perTRP per frequency layer.

The concept of a frequency layer is somewhat like the concept ofcomponent carriers and bandwidth parts (BWPs), but different in thatcomponent carriers and BWPs are used by one base station (or a macrocell base station and a small cell base station) to transmit datachannels, while frequency layers are used by several (usually three ormore) base stations to transmit PRS. A UE may indicate the number offrequency layers it can support when it sends the network itspositioning capabilities, such as during an LTE positioning protocol(LPP) session. For example, a UE may indicate whether it can support oneor four positioning frequency layers.

Note that the terms “positioning reference signal” and “PRS” generallyrefer to specific reference signals that are used for positioning in NRand LTE systems. However, as used herein, the terms “positioningreference signal” and “PRS” may also refer to any type of referencesignal that can be used for positioning, such as but not limited to, PRSas defined in LTE and NR, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB,SRS, UL-PRS, etc. In addition, the terms “positioning reference signal”and “PRS” may refer to downlink or uplink positioning reference signals,unless otherwise indicated by the context. If needed to furtherdistinguish the type of PRS, a downlink positioning reference signal maybe referred to as a “DL-PRS,” and an uplink positioning reference signal(e.g., an SRS-for-positioning, PTRS) may be referred to as an “UL-PRS.”In addition, for signals that may be transmitted in both the uplink anddownlink (e.g., DMRS, PTRS), the signals may be prepended with “UL” or“DL” to distinguish the direction. For example, “UL-DMRS” may bedifferentiated from “DL-DMRS.”

In some designs, on-demand Uu PRS (e.g., DL PRS, UL SRS-P, etc.) isscheduled by the network to reduce overhead associated with periodicbroadcast PRS. Generally, for on-demand Uu PRS, if a UE has noinformation on possible on-demand PRS, the UE may request a desiredcustomized PRS configuration. If a UE has some preconfigured on-demandPRS configuration, the UE may request a specific reconfiguration orswitch to a desired configuration. The network (gNB or LMF) receivesthis request from the UE, and coordinates with TRPs for on-demand PRS.

However, in sidelink environments, centralized scheduling andconfiguration of PRS may suffer from high overhead due to a dynamictopology. For example, a target UE and/or anchor UE(s) may be movingquickly, resulting in frequent SL PRS configuration changes. For atarget UE, the SL PRS configuration should be updated when a SL anchorenters/exits its neighborhood. FIG. 18 illustrates a sidelink zonetopology 1800 in accordance with an aspect of the disclosure. As shownin FIG. 18 , SL anchor UEs may move into and/or out of a respectivesidelink zone where a target UE is located. Each change to the sidelinkzone topology 1800 due to the changing SL anchor UEs may trigger SL PRSreconfiguration, which leads to high reconfiguration overhead.

For this reason, particular SL anchors may not always be available foron-demand PRS in SL. For example, on-demand SL PRS configurations mayhave an expiration timer (e.g., preloaded SL PRS configuration for SLanchors may expire due to anchor movement). In some designs, anexpiration timer may be defined for preloaded on-demand SL-PRSconfiguration. In some designs, timer might depend on UE mobility status(e.g., UEs moving more quickly may have shorter timers, and vice versa).In some designs, the timer may be defined per SL (relative movement). Insome designs, an on-demand SL PRS configuration may be defined in realtime, which may increase latency (e.g., due to backhaul signaling forTRP configuration, and SL anchor configuration involving backhaulsignaling as well as Uu interface).

In some designs, an initiator of an on-demand SL PRS request may be atarget UE, while in other designs an initiator of an on-demand SL PRSrequest may be a position estimation entity (or both, in case ofUE-based position estimation). In some designs, the position estimationentity that coordinates an on-demand SL PRS position estimation sessionmay be a network component (e.g., gNB or LMF, similar to Uu case), whilein other designs the position estimation entity that coordinates anon-demand SL PRS position estimation may be a UE (e.g., self-organizedor UE-to-UE).

Aspects of the disclosure are thereby directed to sidelink anchor groupsthat include a set of sidelink anchors that are each associated with arespective SL PRS “pre”-configuration for one or more future on-demandSL PRS position estimation procedures. As used here, SL PRSpre-configuration refers to an SL PRS configuration that is configuredin a dedicated manner before (i.e., in advance of) an on-demand PRSrequest is received from a UE. In this case, the position estimationentity may then provide assistance data associated with the sidelinkanchor group to the target UE, which may then perform an on-demandsidelink PRS position estimation session with the sidelink anchor group(e.g., based on the SL PRS pre-configuration(s), which may be sent to UEas part of the assistance data or by one or more of the sidelink UEs inthe sidelink anchor groups). Such aspects may provide various technicaladvantages, such as facilitating on-demand SL PRS, which generally isassociated with lower overhead and power consumption as compared toperiodic broadcast SL PRS.

FIG. 19 illustrates an exemplary process 1900 of communication,according to aspects of the disclosure. In an aspect, the process 1900may be performed by a position estimation entity, such as a UE (e.g.,for UE-based position estimation) or a network component (e.g., gNB suchas BS 304 for RAN-integrated LMF, or a core network-integrated LMF or alocation server such as network entity 306, etc.).

Referring to FIG. 19 , at 1910, the position estimation entity (e.g.,receiver 312 or 322 or 352 or 362, transmitter 314 or 324 or 354 or 364,network transceiver(s) 380 or 390, etc.) performs sidelink anchorregistration with a plurality of sidelink anchors. In some designs, thesidelink anchor registration may involve a negotiation or messagingexchange between the position estimation entity and the respectivesidelink anchors. A means for performing the sidelink anchorregistration of 1910 may include receiver 312 or 322 or 352 or 362,transmitter 314 or 324 or 354 or 364, network transceiver(s) 380 or 390,etc., depending on whether the position estimation entity corresponds toUE 302, or gNB such as BS 304 for RAN-integrated LMF, or a corenetwork-integrated LMF or a location server such as network entity 306.

Referring to FIG. 19 , at 1920, the position estimation entity (e.g.,processor(s) 332 or 384 or 394, on-demand PRS component 342 or 388 or398, etc.) configures a sidelink anchor group from among the pluralityof sidelink anchors based on a set of criteria. For example, the set ofcriteria may include a mobility status of the plurality of sidelinkanchors (e.g., exclude sidelink anchors with higher mobility, etc.), aposition estimation accuracy or capability associated with the pluralityof sidelink anchors (e.g., include sidelink anchors with better positionestimation accuracy or more capability, etc.), or a combination thereof.In some designs, the sidelink PRS pre-configuration specifies for eachsidelink anchor in the sidelink anchor group, a first offset from asidelink PRS trigger from the UE to a sidelink PRS transmission from therespective sidelink anchor, an expected reception time of sidelink PRSfrom the UE, or a combination thereof. A means for performing theconfiguration of 1920 may include processor(s) 332 or 384 or 394,on-demand PRS component 342 or 388 or 398, etc., depending on whetherthe position estimation entity corresponds to UE 302, or gNB such as BS304 for RAN-integrated LMF, or a core network-integrated LMF or alocation server such as network entity 306.

Referring to FIG. 19 , at 1930, the position estimation entity (e.g.,transmitter 314 or 324 or 354 or 364, data bus 334, networktransceiver(s) 380 or 390, etc.) transmits, to each sidelink anchor ofthe sidelink anchor group, a respective sidelink PRS pre-configuration.In some designs, if the position estimation entity itself corresponds toone of the sidelink anchors in the sidelink anchor group, then thetransmission at 1930 may include an internal logical transfer of data. Ameans for performing the transmission of 1930 may include transmitter314 or 324 or 354 or 364, data bus 334, network transceiver(s) 380 or390, etc., depending on whether the position estimation entitycorresponds to UE 302, or gNB such as BS 304 for RAN-integrated LMF, ora core network-integrated LMF or a location server such as networkentity 306.

Referring to FIG. 19 , at 1940, the position estimation entity (e.g.,receiver 312 or 322 or 352 or 362, network transceiver(s) 380 or 390,data bus 334, etc.) receives, from a UE, a request to schedule anon-demand sidelink PRS position estimation session of the UE. In anexample, the request at 1940 may be unassociated with the sidelinkanchor group configuration at 1920-1930 (e.g., in other words, 1910-1930may be performed beforehand). A means for performing the reception of1940 may include receiver 312 or 322 or 352 or 362, data bus 334,network transceiver(s) 380 or 390, etc., depending on whether theposition estimation entity corresponds to UE 302, or gNB such as BS 304for RAN-integrated LMF, or a core network-integrated LMF or a locationserver such as network entity 306.

Referring to FIG. 19 , at 1950, the position estimation entity (e.g.,transmitter 314 or 324 or 354 or 364, network transceiver(s) 380 or 390,data bus 334, etc.) transmits, to the UE, a sidelink PRS response thatcomprises assistance data associated with the sidelink anchor group forthe on-demand sidelink PRS position estimation session. For example, theassistance data may include a sidelink anchor group identifier, aprivate key, a resource grant for transmission of a sidelink PRS triggerfrom the UE to the sidelink anchor group, a sidelink PRSpre-configuration associated with the sidelink anchor group for theon-demand sidelink PRS position estimation session, a sidelink anchoridentifier for a sidelink PRS trigger from the UE to the sidelink anchorgroup, or a combination thereof. A means for performing the transmissionof 1950 may include transmitter 314 or 324 or 354 or 364, data bus 334,network transceiver(s) 380 or 390, etc., depending on whether theposition estimation entity corresponds to UE 302, or gNB such as BS 304for RAN-integrated LMF, or a core network-integrated LMF or a locationserver such as network entity 306.

Referring to FIG. 19 , at 1960, the position estimation entity (e.g.,receiver 312 or 322 or 352 or 362, network transceiver(s) 380 or 390,data bus 334, etc.) receives one or more measurement reports associatedwith the on-demand sidelink PRS position estimation session. A means forperforming the reception of 1960 may include receiver 312 or 322 or 352or 362, data bus 334, network transceiver(s) 380 or 390, etc., dependingon whether the position estimation entity corresponds to UE 302, or gNBsuch as BS 304 for RAN-integrated LMF, or a core network-integrated LMFor a location server such as network entity 306.

FIG. 20 illustrates an exemplary process 2000 of wireless communication,according to aspects of the disclosure. In an aspect, the process 2000may be performed by a UE, such as UE 302. In particular, the UE thatperforms the process 2000 of FIG. 20 corresponds to a UE for which aposition estimate is desired, generally referred to as a target UE.

Referring to FIG. 20 , at 2010, UE 302 (e.g., transmitter 314 or 324,data bus 334, etc.) transmits, to a position estimation entity, arequest to schedule an on-demand sidelink PRS position estimationsession of the UE. A means for performing the transmission of 2010 mayinclude transmitter 314 or 324, data bus 334, etc., of UE 302.

Referring to FIG. 20 , at 2020, UE 302 (e.g., receiver 312 or 322, databus 334, etc.) receives, from the position estimation entity, a sidelinkPRS response that comprises assistance data associated with a sidelinkanchor group for the on-demand sidelink PRS position estimation session.In some designs, the assistance data comprises a sidelink anchor groupidentifier, a private key, a resource grant for transmission of asidelink PRS trigger from the UE to the sidelink anchor group, asidelink PRS pre-configuration associated with the sidelink anchor groupfor the on-demand sidelink PRS position estimation session, a sidelinkanchor identifier for sidelink PRS trigger from the UE to the sidelinkanchor group, or a combination thereof. A means for performing thereception of 2020 may include receiver 312 or 322, data bus 334, etc.,of UE 302.

Referring to FIG. 20 , at 2030, UE 302 (e.g., transmitter 314 or 324,data bus 334, etc.) transmits, to the sidelink anchor group, a sidelinkPRS trigger to trigger the on-demand sidelink PRS position estimationsession in accordance with respective sidelink PRS pre-configurations ofthe sidelink anchor. In some designs, the sidelink PRS trigger istransmitted via multicast or broadcast (e.g., alternatively, N unicasttransmissions can be made to N sidelink anchors). In some designs, thesidelink PRS trigger comprises an indication of a sidelink zone in whichthe UE is located. In some designs, the sidelink PRS trigger designatesa maximum range between the UE and a respective sidelink anchor for therespective sidelink anchor to accept the sidelink PRS trigger. In somedesigns, UE 302 may further receive, from at least one sidelink anchorof the sidelink anchor group, a sidelink PRS trigger response (e.g., thesidelink PRS trigger response indicates acceptance or rejection of thesidelink PRS trigger, and may include other information as will bediscussed below in more detail). A means for performing the transmissionof 2030 may include transmitter 314 or 324, data bus 334, etc., of UE302.

Referring to FIG. 20 , at 2040, UE 302 (e.g., receiver 312 or 322,transmitter 314 or 324, etc.) performs a sidelink PRS exchange with oneor more sidelink anchors of the sidelink anchor group in associationwith the on-demand sidelink PRS position estimation session. In somedesigns, the sidelink PRS exchange includes a two-way PRS exchangebetween the UE and each respective sidelink anchor in the anchor group(e.g., UE sends SL PRS to sidelink anchor, which responds with SL PRS,or vice versa, e.g., for RTT measurements, such as Tx-Rx, etc.), or aone-way PRS exchange (e.g., from UE to each sidelink anchor, or eachsidelink anchor to UE, e.g., for TDOA measurements), or some combinationthereof. In some designs, the sidelink PRS exchange comprises blinddecoding and/or descrambling only for SL PRS sidelink anchors from whicha respective sidelink PRS trigger response that indicates acceptance ofthe sidelink PRS trigger is received. In other designs, the sidelink PRSexchange comprises blind decoding and/or descrambling for SL PRS foreach sidelink anchor among the sidelink anchor group. In some designs,UE 302 may further transmit a measurement report based on the sidelinkPRS exchange to the position estimation entity. A means for performingthe sidelink PRS exchange of 2040 may include receiver 312 or 322,transmitter 314 or 324, etc., of UE 302.

FIG. 21 illustrates an exemplary process 2100 of wireless communication,according to aspects of the disclosure. In an aspect, the process 2100may be performed by a sidelink anchor, which may correspond to a UE suchas UE 302. In some designs, to qualify as a sidelink anchor, thesidelink anchor may be associated with a known location (e.g., from arecent position estimation fix, etc.).

Referring to FIG. 21 , at 2110, the sidelink anchor (e.g., receiver 312or 322, transmitter 314 or 324, data bus 334, etc.) performs sidelinkanchor registration with a position estimation entity. In some designs,the sidelink anchor registration may involve a negotiation or messagingexchange between the position estimation entity and the sidelink anchor.A means for performing the sidelink anchor registration of 2110 mayinclude receiver 312 or 322, transmitter 314 or 324, data bus 334, etc.,of UE 302.

Referring to FIG. 21 , at 2120, the sidelink anchor (e.g., receiver 312or 322, data bus 334, etc.) receives, from the position estimationentity in response to the sidelink anchor registration, a sidelink PRSpre-configuration associated with a sidelink anchor group. In somedesigns, the sidelink PRS pre-configuration specifies a first offsetfrom a sidelink PRS trigger from the UE to a sidelink PRS transmissionfrom the sidelink anchor, an expected reception time of sidelink PRSfrom the UE, or a combination thereof. A means for performing thereception of 2120 may include receiver 312 or 322, data bus 334, etc.,of UE 302.

Referring to FIG. 21 , at 2130, the sidelink anchor (e.g., receiver 312or 322, etc.) receives, from a UE, a sidelink PRS trigger that triggersthe sidelink PRS pre-configuration for an on-demand sidelink PRSposition estimation session of the UE with the sidelink anchor group. Insome designs, the sidelink PRS trigger is transmitted via multicast orbroadcast (e.g., alternatively, N unicast transmissions can be made to Nsidelink anchors). In some designs, the sidelink PRS trigger comprisesan indication of a sidelink zone in which the UE is located. In somedesigns, the sidelink PRS trigger designates a maximum range between theUE and a respective sidelink anchor for the respective sidelink anchorto accept the sidelink PRS trigger. In some designs, the sidelink anchormay determine to participate in the on-demand sidelink PRS positionestimation session with the UE based on one or more criteria. Forexample, the sidelink PRS trigger comprises an indication of a sidelinkzone in which the UE is located, and the one or more criteria comprisesa relationship between the sidelink anchor and the sidelink zone inwhich the UE is located. In other designs, the sidelink PRS triggerdesignates a maximum range between the UE and a respective sidelinkanchor for the respective sidelink anchor to accept the sidelink PRStrigger, and the determination is based on whether the sidelink anchoris inside of the maximum range. In some designs, the sidelink UE mayfurther transmit, to the UE, a sidelink PRS trigger response (e.g., thesidelink PRS trigger response indicates acceptance of the sidelink PRStrigger). A means for performing the reception of 2130 may includereceiver 312 or 322, of UE 302.

Referring to FIG. 21 , at 2140, the sidelink anchor (e.g., receiver 312or 322, transmitter 314 or 324, etc.) performs a sidelink PRS exchangewith the UE associated with the on-demand sidelink PRS positionestimation session in response to the sidelink PRS trigger. In somedesigns, the sidelink PRS exchange includes a two-way PRS exchangebetween the UE and the sidelink anchor in the anchor group (e.g., UEsends SL PRS to sidelink anchor, which responds with SL PRS, or viceversa, e.g., for RTT measurements, such as Tx-Rx, etc.), or a one-wayPRS exchange (e.g., from UE to each sidelink anchor, or each sidelinkanchor to UE, e.g., for TDOA measurements), or some combination thereof.In some designs, the sidelink anchor may further transmit a measurementreport based on the sidelink PRS exchange to the position estimationentity. A means for performing the sidelink PRS exchange of 2140 mayinclude receiver 312 or 322, transmitter 314 or 324, etc., of UE 302.

FIG. 22 illustrates an example implementation 2200 of the processes1900-2100 of FIGS. 19-21 , respectively, in accordance with an aspect ofthe disclosure. In particular, the example implementation 2200 involvesa sidelink PRS procedure between a target UE and sidelink anchors 1-3.

Referring to FIG. 22 , at 2202, sidelink anchor registration isperformed between sidelink anchors 1-3 and a position estimation entity.For example, at 2202, SL anchor capability (support for SL-PRS, etc.) isnegotiated. Here, three UEs (sidelink anchors 1-3) are registered assidelink anchors 1-3. The position estimation entity may determinevarious information associated with the sidelink anchors 1-3, such aslocation, mobility status (e.g., mobile or stationary), power supplylevel, whether the sidelink anchors have an ongoing LPP session, anumber of active SL connections, etc. Such information may be obtainedat 2202 as part of UE capability report or per LMF inquiry.

Referring to FIG. 22 , at 2204, SL PRS pre-configurations are sent bythe position estimation entity to sidelink anchors 1-3. For example, asubset of SL anchors (here, SL anchors 1-3) are selected by positioningentity as one sidelink anchor group. The selection might be based onprevious estimation ensuring a reasonable Geometric dilution ofprecision (GDOP) for UE within a region. In some designs, slow-moving orsemi-static UEs (customer premise equipment (CPE), RSU, slow moving UEetc.) may be selected as sidelink anchors for a sidelink anchor group(e.g., similar to TRPs in Uu). In some designs, the selection might bebased on SL-zone (e.g., one SL-anchor (delegate) per zone, or some othermaximum number). In some designs, sidelink anchors may be selected toprovide a dynamic layout (e.g., avoid clusters of sidelink anchors in asingle zone, etc.). In some designs, selection might be based on UElocation estimate accuracy/capability, etc. In some designs, SL PRSpre-configuration for sidelink anchors may include SL PRS frequencylayer, time scheduling (e.g., Ksl1 which denotes a transmission timeafter the sidelink anchor receives the trigger, and/or Ksl2 whichdenotes an expected reception time (SLRTT) of SL PRS from the UE),anchor group ID. In some designs, a public key assigned by LMF to SLanchors to decrypt target UE SL PRS trigger.

Referring to FIG. 22 , at 2206, the target UE transmits SL PRS requestto the position estimation entity. At 2208, the position estimationentity transmits SL PRS pre-configuration to the target UE (e.g.,assistance data). For example, the position estimation entity mayprovide anchor group ID and/or private key, an anchor group designationwith a reasonable GDOP coverage, a resource grant for SL PRS trigger, SLPRS pre-configuration(s) associated with the sidelink anchor group, SLanchor IDs for group-based request, etc. By contrast, if following Uuscheme, LMF may send trigger to multiple SL anchors, which may causeextra overhead and latency.

Referring to FIG. 22 , at 2210, the target UE transmits SL PRS triggerto sidelink anchors 1-3. For example, the target UE broadcasts/groupcastthe SL PRS trigger through SL. In some designs, the SL PRS triggercontains the anchor group ID and key (e.g., RNTI). In some designs, theSL PRS trigger adds its own zone ID for distance/proximity-basedresponse (e.g., sidelink anchors in sidelink anchor group based onspatial relationship or distance to the target UE). In some designs, theSL PRS trigger may further define a maximum range for response and SLPRS (e.g., maximum {X} meters or maximum Y zones). In some designs, theSL PRS trigger may further indicate whether SL-PRS is aperiodic orsemi-persistent. In some designs, the SL PRS trigger may furtherindicate a number of PRS instances in the request for semi-persistentSL-PRS. In some designs, on-demand SL PRS cancellation may be performedif necessary to accommodate higher-priority SL traffic

Referring to FIG. 22 , at 2212, sidelink anchors (optionally) transmitSL PRS responses. In some designs, SL anchors that received the SL PRStrigger may NACK/ACK the SL PRS trigger through SL. Here, ACK indicatesacceptance of the SL PRS trigger rather than mere receipt of the SL PRStrigger, and ACK indicates rejection of the SL PRS trigger. In somedesigns, a receiver UE (SL-anchor) sends ACK if the sidelink anchor iswithin the maximum range. In some designs, receiver UE (SL-anchor) sendsNACK if the sidelink anchor is not available due to scheduling conflict.In some designs, SL PRS responses could further reduce the SL-PRSblind-search overhead, especially for semi-persistent SL-PRS. This comeswith the cost of extra signaling overhead. For aperiodic SL-PRS, in somedesigns, SL PRS responses can be skipped and target UE can blind decodeand/or descramble for every potential SL-anchors (e.g., for all SL PRSpre-configurations received at 2208). In this case, sidelink anchors 2-3transmit SL PRS responses, and sidelink anchor 1 may opt out of the SLPRS position estimation procedure.

Referring to FIG. 22 , at 2214-2216, a SL PRS exchange is performedbetween sidelink anchors 2-3 and the target UE. In this case, sidelinkanchors 2-3 transmit SL PRS at 2214, and the target UE transmits SL PRSat 2216. In some designs, SL anchors in the required anchor group whoreceive the trigger may be expected to exchange SL-PRS with target UE.In some designs, a distance/proximity constraint may further requireparticipating SL anchors to satisfy the distance requirements. In somedesigns, the distance can be computed from target UE zone ID and Rx UE(sidelink anchor) location. In some designs, zone distance can becomputed from target UE zone ID and anchor zone ID. If zone based, theSL anchor in the same zone may ignore the request to reserve the SL-PRSsequence for target UE.

Referring to FIG. 22 , at 2218 sidelink anchors 2-3, the target UE or acombination thereof transmit measurement report(s) to the positionestimation entity. In some designs, independent reports may betransmitted by each UE (additional LPP sessions). In other designs, thetarget UE may consolidate measurement data from the sidelink anchors2-3, and then send one report to the position estimation entity (one LPPsession).

FIG. 23 illustrates a sidelink anchor group configuration 2300 inaccordance with aspects of the disclosure. In particular, the sidelinkanchor group configuration 2300 may be based upon execution of theprocesses 1900-2100 of FIGS. 19-21 . In FIG. 23 , sidelink anchor groupconfiguration 2300 includes a sidelink anchor group with a maximum ofone sidelink anchor per-zone within a single adjacent zone from a targetUE.

While FIGS. 19-23 relate generally to on-demand SL PRS positionestimation that is centrally controlled by a position estimation entitybased on a designated sidelink anchor group, in other designs, dynamicsidelink anchor groups may be utilized. For example, a set ofproximity-based sidelink PRS pre-configurations for on-demand PRSposition estimation, and a target UE and sidelink anchor(s) may thensetup an on-demand PRS position estimation session without furthercoordination with the position estimation entity. Such aspects mayprovide various technical advantages, such as facilitating on-demand SLPRS, which generally is associated with lower overhead and powerconsumption as compared to periodic broadcast SL PRS. Also, facilitatingdecentralized on-demand SL PRS may provide additional technicaladvantages, such as simplifying the on-demand SL PRS procedure, reducingconfiguration latency, and reducing beam pairing overhead.

FIG. 24 illustrates an exemplary process 2400 of communication,according to aspects of the disclosure. In an aspect, the process 2400may be performed by a position estimation entity, such as a UE (e.g.,for UE-based position estimation) or a network component (e.g., gNB suchas BS 304 for RAN-integrated LMF, or a core network-integrated LMF or alocation server such as network entity 306, etc.).

Referring to FIG. 24 , at 2410, the position estimation entity (e.g.,receiver 312 or 322 or 352 or 362, transmitter 314 or 324 or 354 or 364,network transceiver(s) 380 or 390, etc.) performs sidelink anchorregistration with a plurality of sidelink anchors distributed throughouta plurality of sidelink zones. In some designs, the plurality ofsidelink zones is associated with a non-public network (NPN) (e.g., anIIoT factory environment, etc.). In some designs, the sidelink anchorregistration may involve a negotiation or messaging exchange between theposition estimation entity and the respective sidelink anchors. A meansfor performing the sidelink anchor registration of 2410 may includereceiver 312 or 322 or 352 or 362, transmitter 314 or 324 or 354 or 364,network transceiver(s) 380 or 390, etc., depending on whether theposition estimation entity corresponds to UE 302, or gNB such as BS 304for RAN-integrated LMF, or a core network-integrated LMF or a locationserver such as network entity 306.

Referring to FIG. 24 , at 2420, the position estimation entity (e.g.,transmitter 314 or 324 or 354 or 364, data bus 334, networktransceiver(s) 380 or 390, etc.) transmits, to the plurality of sidelinkanchors and a UE, a set of proximity-based sidelink PRSpre-configurations for on-demand PRS position estimation. In somedesigns, each proximity-based sidelink PRS pre-configuration of the setof proximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof. In some designs, the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones. In some designs, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters. In some designs, the plurality of sidelink anchors based ona sidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone (e.g., based on one or more of UE capability,mobility status, power supply, position estimation accuracy, or acombination thereof). A means for performing the transmission of 2420may include transmitter 314 or 324 or 354 or 364, network transceiver(s)380 or 390, etc., depending on whether the position estimation entitycorresponds to UE 302, or gNB such as BS 304 for RAN-integrated LMF, ora core network-integrated LMF or a location server such as networkentity 306.

Referring to FIG. 24 , at 2430, the position estimation entity (e.g.,receiver 312 or 322 or 352 or 362, network transceiver(s) 380 or 390,etc.) receives one or more measurement reports associated with anon-demand sidelink PRS position estimation session between the UE and adynamic sidelink anchor group that is determined in accordance with theset of proximity-based sidelink PRS pre-configurations. The measurementreport(s) may be received from a single UE or multiple UEs associatedwith the on-demand sidelink PRS position estimation session. A means forperforming the reception of 2430 may include receiver 312 or 322 or 352or 362, network transceiver(s) 380 or 390, etc., depending on whetherthe position estimation entity corresponds to UE 302, or gNB such as BS304 for RAN-integrated LMF, or a core network-integrated LMF or alocation server such as network entity 306.

FIG. 25 illustrates an exemplary process 2500 of wireless communication,according to aspects of the disclosure. In an aspect, the process 2500may be performed by a UE, such as UE 302. In particular, the UE thatperforms the process 2500 of FIG. 21 corresponds to a UE for which aposition estimate is desired, generally referred to as a target UE.

Referring to FIG. 25 , at 2510, UE 302 (e.g., receiver 312 or 322, databus 334, etc.) receives, from a position estimation entity, a set ofproximity-based sidelink PRS pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones. In some designs,each proximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof. In some designs, the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones. In some designs, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters. In some designs, the plurality of sidelink anchors based ona sidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone (e.g., based on one or more of UE capability,mobility status, power supply, position estimation accuracy, or acombination thereof). In some designs, the plurality of sidelink zonesis associated with a non-public network (NPN) (e.g., an IIoT factoryenvironment, etc.). A means for performing the reception of 2510 mayinclude receiver 312 or 322, data bus 334, etc., of UE 302.

Referring to FIG. 25 , at 2520, UE 302 (e.g., transmitter 314 or 324,data bus 334, etc.) transmits, a sidelink PRS trigger to trigger anon-demand sidelink PRS position estimation session with a dynamicsidelink anchor group, the sidelink PRS trigger configured to indicate asidelink zone associated with the UE and a proximity requirement forparticipation in the on-demand sidelink PRS position estimation. In somedesigns, the proximity requirement designates a maximum distance fromthe sidelink zone associated with the UE, a minimum distance from thesidelink zone associated with the UE, or a combination thereof. A meansfor performing the transmission of 2520 may include transmitter 314 or324, data bus 334, etc., of UE 302.

Referring to FIG. 25 , at 2530, UE 302 (e.g., receiver 312 or 322,transmitter 314 or 324, etc.) performs a sidelink PRS exchange with thedynamic sidelink anchor group in association with the on-demand sidelinkPRS position estimation session based on one or more proximity-basedsidelink PRS pre-configurations from the set of proximity-based sidelinkPRS pre-configurations. In some designs, the sidelink PRS exchangeincludes a two-way PRS exchange between the UE and each respectivesidelink anchor in the dynamic sidelink anchor group (e.g., UE sends SLPRS to sidelink anchor, which responds with SL PRS, or vice versa, e.g.,for RTT measurements, such as Tx-Rx, etc.), or a one-way PRS exchange(e.g., from UE to each sidelink anchor, or each sidelink anchor to UE,e.g., for TDOA measurements), or some combination thereof. In somedesigns, one or more beams for the sidelink PRS exchange are determinedbased on a spatial relationship between the sidelink zone associatedwith the UE and one or more sidelink zones associated with the dynamicsidelink anchor group. In some designs, the sidelink PRS exchangecomprises blind decoding and/or descrambling for sidelink PRS from thedynamic sidelink anchor group in accordance with a zone-specificsequence, or the sidelink PRS exchange comprises selective decodingand/or descrambling for sidelink PRS from the dynamic sidelink anchorgroup based on feedback to the sidelink PRS trigger from the dynamicsidelink anchor group. A means for performing the sidelink PRS exchangeof 2530 may include receiver 312 or 322, transmitter 314 or 324, etc.,of UE 302.

FIG. 26 illustrates an exemplary process 2600 of wireless communication,according to aspects of the disclosure. In an aspect, the process 2600may be performed by a sidelink anchor, which may correspond to a UE suchas UE 302. In some designs, to qualify as a sidelink anchor, thesidelink anchor may be associated with a known location (e.g., from arecent position estimation fix, etc.).

Referring to FIG. 26 , at 2610, the sidelink anchor (e.g., receiver 312or 322, transmitter 314 or 324, data bus 334, etc.) performs sidelinkanchor registration with a position estimation entity. In some designs,the sidelink anchor registration may involve a negotiation or messagingexchange between the position estimation entity and the sidelink anchor.A means for performing the sidelink anchor registration of 2610 mayinclude receiver 312 or 322, transmitter 314 or 324, data bus 334, etc.,of UE 302.

Referring to FIG. 26 , at 2620, the sidelink anchor (e.g., receiver 312or 322, data bus 334, etc.) receives, from the position estimationentity, a set of proximity-based sidelink PRS pre-configurations foron-demand PRS position estimation, the set of proximity-based sidelinkPRS pre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones. In some designs,the plurality of sidelink zones is associated with a non-public network(NPN) (e.g., an IIoT factory environment, etc.). In some designs, eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof. In some designs, the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones. In some designs, the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters. In some designs, the plurality of sidelink anchors based ona sidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone (e.g., based on one or more of UE capability,mobility status, power supply, position estimation accuracy, or acombination thereof). A means for performing the reception of 2620 mayinclude receiver 312 or 322, data bus 334, etc., of UE 302.

Referring to FIG. 26 , at 2630, the sidelink anchor (e.g., receiver 312or 322, etc.) receives, from a UE, a sidelink PRS trigger to trigger anon-demand sidelink PRS position estimation session with a dynamicsidelink anchor group, the sidelink PRS trigger configured to indicate asidelink zone associated with the UE and a proximity requirement forparticipation in the on-demand sidelink PRS position estimation. In somedesigns, the proximity requirement designates a maximum distance fromthe sidelink zone associated with the UE, a minimum distance from thesidelink zone associated with the UE, or a combination thereof. A meansfor performing the reception of 2630 may include receiver 312 or 322, ofUE 302.

Referring to FIG. 26 , at 2640, the sidelink anchor (e.g., processor(s)332, on-demand PRS component 342, etc.) determines that the sidelinkanchor satisfies the proximity requirement to the sidelink zone. Thedetermination of 2640 may be performed in various ways, as will bedescribed below in greater detail. A means for performing thedetermination of 2640 may include receiver 312 or 322, of UE 302.

Referring to FIG. 26 , at 2650, the sidelink anchor (e.g., processor(s)332, on-demand PRS component 342, etc.) selects at least oneproximity-based sidelink PRS pre-configuration from the set ofproximity-based sidelink PRS pre-configurations based on a proximitybetween the sidelink anchor and the sidelink zone associated with theUE. The selection of 2650 may be performed in various ways, as will bedescribed below in greater detail. A means for performing the selectionof 2650 may include receiver 312 or 322, of UE 302.

Referring to FIG. 26 , at 2660, the sidelink anchor (e.g., receiver 312or 322, transmitter 314 or 324, etc.) performs a sidelink PRS exchangewith the UE associated with the on-demand sidelink PRS positionestimation session based on the determination and in accordance with theat least one selected proximity-based sidelink PRS pre-configuration. Insome designs, the sidelink PRS exchange includes a two-way PRS exchangebetween the UE and the sidelink anchor i (e.g., UE sends SL PRS tosidelink anchor, which responds with SL PRS, or vice versa, e.g., forRTT measurements, such as Tx-Rx, etc.), or a one-way PRS exchange (e.g.,from UE to sidelink anchor, or sidelink anchor to UE, e.g., for TDOAmeasurements), or some combination thereof. In some designs, one or morebeams for the sidelink PRS exchange are determined based on a spatialrelationship between the sidelink zone associated with the UE and one ormore sidelink zones associated with the dynamic sidelink anchor group.In some designs, the sidelink anchor may transmit a response to thesidelink PRS trigger to facilitate the sidelink PRS exchange between theUE and the sidelink anchor (e.g., ACK/NACK to reduce blind decodingand/or descrambling at target UE, etc.). A means for performing thesidelink PRS exchange of 2660 may include receiver 312 or 322,transmitter 314 or 324, etc., of UE 302.

FIG. 27 illustrates an example implementation 2700 of the processes2400-2600 of FIGS. 24-26 , respectively, in accordance with an aspect ofthe disclosure. In particular, the example implementation 2700 involvesa sidelink PRS procedure between a target UE and sidelink anchors 1-3.

Referring to FIG. 27 , assume that sidelink anchors 1-3 are registeredas sidelink anchor registration with a position estimation entity. At2702, a set of proximity-based sidelink PRS pre-configurations is sentto each of sidelink anchors 1-3, and also to a target UE. In somedesigns, the set of proximity-based sidelink PRS pre-configurations isbased on proximity size. FIG. 28 illustrates sidelink zoneconfigurations in accordance with aspects of the disclosure. At 2800, a9-zone configuration is depicted (e.g., maximum zone distance of 1 fromtarget UE), and at 2850, a 25-zone configuration (e.g., maximum zonedistance of 2 from target UE). Here, the zone configurations 2800-2850may be used to define the set of proximity-based sidelink PRSpre-configurations, as shown in FIG. 29 . In FIG. 29 , at 2900, a set ofproximity-based sidelink PRS pre-configurations is shown a 9-zoneconfiguration (4 proximity-based sidelink PRS pre-configurations foreach of 8 adjacent neighbor zones to a zone of a target UE). In FIG. 29, at 2950, a set of proximity-based sidelink PRS pre-configurations isshown for a 25-zone configuration (6 proximity-based sidelink PRSpre-configurations for each of 24 neighbor zones to a zone of a targetUE). In FIG. 29 , the proximity-based sidelink PRS pre-configurationshave a semi-static configuration.

Referring to FIG. 27 , in some designs, set of proximity-based sidelinkPRS pre-configurations may include parameters such as SL PRS frequencylayer and frequency layer, time scheduling of each zone (e.g., Ksl1 andKsl2, as described above), comb type and muting pattern, and so on. Insome designs, a PRS sequence ID need not be assigned for each sidelinkanchor or target UE, as the PRS sequence ID may instead be determinedvia SL zone identifier. In some designs, the set of proximity-basedsidelink PRS pre-configurations (e.g., 1-4 in 2900 of FIG. 29 , or 1-6in 2950 of FIG. 29 ) may be associated with different timings. Forexample, sidelink anchors in zones “1” may use comb2 in slot 1, sidelinkanchors in zones “2” may use comb2 in slot 2, and so on. In somedesigns, SL anchor management/selection may be performed in azone-specific manner. For example, each zone may have multiple candidateSL anchors. If all candidate SL anchors transmit and receive SL PRS,poor performance may result. In some designs, the position estimationentity (e.g., LMF, etc.) may select one UE (or some maximum number ofUEs) in a zone as a delegate (e.g., based on UE capability, mobilitystatus, power supply, estimation accuracy, etc.

Referring to FIG. 27 , in some designs, proper time and spatialscheduling may efficiently reduce the SL-beam pairing overhead for bothtarget UE and SL anchor UEs. For example, given the spatial relationsbetween zones, both UEs can estimate the best beams for SL-PRS assumingtheir orientations are known. In an example, SL anchors in zones “5” ofthe 25-zone configuration 2950 of FIG. 29 and target UE may have priorknowledge of the relative direction of each other, so that thecorresponding Rx/Tx beams can be tuned.

Referring to FIG. 27 , at 2704, instead of transmitting SL PRS requestto the position estimation entity as at 2206 of FIG. 22 , the target UEinstead transmits SL PRS trigger via SL broadcast or SL groupcast. Forexample, the SL PRS trigger includes the zone identifier for the targetUE and proximity requirement(s) (e.g., maximum of 1 zone distance for9-zone configuration, maximum of 2 zone distance for 25-zoneconfiguration, etc.).

Referring to FIG. 27 , at 2706, sidelink anchors (optionally) transmitSL PRS responses. In some designs, SL anchors that satisfy the proximityrequirement(s) of the SL PRS trigger may ACK the SL PRS trigger throughSL. In this case, sidelink anchors 2-3 transmit SL PRS responses, andsidelink anchor 1 may opt out of the SL PRS position estimationprocedure.

Referring to FIG. 27 , at 2708-2710, a SL PRS exchange is performedbetween sidelink anchors 2-3 and the target UE. In this case, sidelinkanchors 2-3 transmit SL PRS at 2708, and the target UE transmits SL PRSat 2710. In some designs, SL anchors who receive the SL PRS trigger andmeet the requirements are activated for on-demand PRS. In some designs,SL anchor transmits SL PRS using scheduled slot offset and SL-PRS FL andzone-based SL-PRS ID. In some designs, the target UE receives SL PRSusing scheduled slot offset and SL-PRS FL and blind search using thescheduled zone sequence. With additional feedback (ACK/NACK) from SLanchors, target UE may not need to blind decode and/or descramble. Whilenot shown in FIG. 27 , the target UE or a combination thereof transmitmeasurement report(s) to the position estimation entity. In somedesigns, independent reports may be transmitted by each UE (additionalLPP sessions). In other designs, the target UE may consolidatemeasurement data from the sidelink anchors 2-3, and then send one reportto the position estimation entity (one LPP session).

Referring to FIGS. 24-26 , in some designs, the plurality of sidelinkzones comprises at least one dead zone where Uu-based positionestimation does not satisfy an accuracy requirement. For example, due toblockage problems, there might be some positioning dead zones where thepositioning accuracy requirement cannot be met using Uu only. In somedesigns, on-demand PRS measurements report can be considered a feedbackof dead zone region (e.g., if a frequency or probability of on-demand SLis high in certain SL zones, the LMF may gradually understands that thisSL-zone may be considered as dead zone). The LMF may then associate thedead zone region with respective SL zone IDs. LMF may further provideassistance data (e.g., to UEs in the region via SIB, etc.) about thedead zone location using the SL-zone ID.

FIG. 30 illustrates a 25-zone configuration 3000 that includes 3 deadzones. In some designs, the position estimation entity instructs the UEto trigger the on-demand sidelink PRS position estimation session uponentry into the at least one dead zone. Alternatively, the positionestimation entity triggers the on-demand sidelink PRS positionestimation session upon detection that the UE has entered into the atleast one dead zone.

In the detailed description above it can be seen that different featuresare grouped together in examples. This manner of disclosure should notbe understood as an intention that the example clauses have morefeatures than are explicitly mentioned in each clause. Rather, thevarious aspects of the disclosure may include fewer than all features ofan individual example clause disclosed. Therefore, the following clausesshould hereby be deemed to be incorporated in the description, whereineach clause by itself can stand as a separate example. Although eachdependent clause can refer in the clauses to a specific combination withone of the other clauses, the aspect(s) of that dependent clause are notlimited to the specific combination. It will be appreciated that otherexample clauses can also include a combination of the dependent clauseaspect(s) with the subject matter of any other dependent clause orindependent clause or a combination of any feature with other dependentand independent clauses. The various aspects disclosed herein expresslyinclude these combinations, unless it is explicitly expressed or can bereadily inferred that a specific combination is not intended (e.g.,contradictory aspects, such as defining an element as both an insulatorand a conductor). Furthermore, it is also intended that aspects of aclause can be included in any other independent clause, even if theclause is not directly dependent on the independent clause.

Implementation examples are described in the following numbered clauses:

Clause 1. A method of operating a position estimation entity,comprising: performing sidelink anchor registration with a plurality ofsidelink anchors distributed throughout a plurality of sidelink zones;transmitting, to the plurality of sidelink anchors and a user equipment(UE), a set of proximity-based sidelink positioning reference signal(PRS) pre-configurations for on-demand PRS position estimation; andreceiving one or more measurement reports associated with an on-demandsidelink PRS position estimation session between the UE and a dynamicsidelink anchor group that is determined in accordance with the set ofproximity-based sidelink PRS pre-configurations.

Clause 2. The method of clause 1, wherein the plurality of sidelinkzones is associated with a non-public network (NPN).

Clause 3. The method of any of clauses 1 to 2, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 4. The method of any of clauses 1 to 3, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones.

Clause 5. The method of any of clauses 1 to 4, wherein the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters.

Clause 6. The method of any of clauses 1 to 5, further comprising:selecting the plurality of sidelink anchors based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone.

Clause 7. The method of clause 6, wherein the selection is based on oneor more of UE capability, mobility status, power supply, positionestimation accuracy, or a combination thereof.

Clause 8. The method of any of clauses 1 to 7, wherein the plurality ofsidelink zones comprises at least one dead zone where Uu-based positionestimation does not satisfy an accuracy requirement.

Clause 9. The method of clause 8, wherein the position estimation entityinstructs the UE to trigger the on-demand sidelink PRS positionestimation session upon entry into the at least one dead zone, orwherein the position estimation entity triggers the on-demand sidelinkPRS position estimation session upon detection that the UE has enteredinto the at least one dead zone.

Clause 10. A method of operating a user equipment (UE), comprising:receiving, from a position estimation entity, a set of proximity-basedsidelink positioning reference signal (PRS) pre-configurations foron-demand PRS position estimation, the set of proximity-based sidelinkPRS pre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; transmitting asidelink PRS trigger to trigger an on-demand sidelink PRS positionestimation session with a dynamic sidelink anchor group, the sidelinkPRS trigger configured to indicate a sidelink zone associated with theUE and a proximity requirement for participation in the on-demandsidelink PRS position estimation; and performing a sidelink PRS exchangewith the dynamic sidelink anchor group in association with the on-demandsidelink PRS position estimation session based on one or moreproximity-based sidelink PRS pre-configurations from the set ofproximity-based sidelink PRS pre-configurations.

Clause 11. The method of clause 10, further comprising: determining oneor more beams for the sidelink PRS exchange based on a spatialrelationship between the sidelink zone associated with the UE and one ormore sidelink zones associated with the dynamic sidelink anchor group.

Clause 12. The method of any of clauses 10 to 11, wherein the proximityrequirement designates a maximum distance from the sidelink zoneassociated with the UE, a minimum distance from the sidelink zoneassociated with the UE, or a combination thereof.

Clause 13. The method of any of clauses 10 to 12, wherein the sidelinkPRS exchange comprises blind decoding or descrambling for sidelink PRSfrom the dynamic sidelink anchor group in accordance with azone-specific sequence, or wherein the sidelink PRS exchange comprisesselective decoding or descrambling for sidelink PRS from the dynamicsidelink anchor group based on feedback to the sidelink PRS trigger fromthe dynamic sidelink anchor group.

Clause 14. The method of any of clauses 10 to 13, wherein the pluralityof sidelink zones is associated with a non-public network (NPN).

Clause 15. The method of any of clauses 10 to 14, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 16. The method of any of clauses 10 to 15, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones.

Clause 17. The method of any of clauses 10 to 16, wherein the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters.

Clause 18. The method of any of clauses 10 to 17, wherein the pluralityof sidelink anchors is distributed across the plurality of sidelinkzones based on a sidelink anchor constraint that limits a number ofsidelink anchors assigned per sidelink zone.

Clause 19. The method of any of clauses 10 to 18, wherein the pluralityof sidelink zones comprises at least one dead zone where Uu-basedposition estimation does not satisfy an accuracy requirement.

Clause 20. The method of clause 19, wherein the position estimationentity instructs the UE to trigger the on-demand sidelink PRS positionestimation session upon entry into the at least one dead zone, orwherein the position estimation entity triggers the on-demand sidelinkPRS position estimation session upon detection that the UE has enteredinto the at least one dead zone.

Clause 21. A method of operating a sidelink anchor, comprising:performing sidelink anchor registration with a position estimationentity; receiving, from the position estimation entity, a set ofproximity-based sidelink PRS pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; receiving, from auser equipment (UE), a sidelink PRS trigger to trigger an on-demandsidelink PRS position estimation session with a dynamic sidelink anchorgroup, the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; determining that thesidelink anchor satisfies the proximity requirement to the sidelinkzone; selecting at least one proximity-based sidelink PRSpre-configuration from the set of proximity-based sidelink PRSpre-configurations based on a proximity between the sidelink anchor andthe sidelink zone associated with the UE; performing a sidelink PRSexchange with the UE associated with the on-demand sidelink PRS positionestimation session based on the determination and in accordance with theat least one selected proximity-based sidelink PRS pre-configuration.

Clause 22. The method of clause 21, further comprising: determining oneor more beams for the sidelink PRS exchange based on a spatialrelationship between the sidelink zone associated with the UE and asidelink zone associated with the sidelink anchor.

Clause 23. The method of any of clauses 21 to 22, wherein the proximityrequirement designates a maximum distance from the sidelink zoneassociated with the UE, a minimum distance from the sidelink zoneassociated with the UE, or a combination thereof.

Clause 24. The method of any of clauses 21 to 23, further comprising:transmitting a response to the sidelink PRS trigger to facilitate thesidelink PRS exchange between the UE and the sidelink anchor.

Clause 25. The method of any of clauses 21 to 24, wherein the pluralityof sidelink zones is associated with a non-public network (NPN).

Clause 26. The method of any of clauses 21 to 25, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 27. The method of any of clauses 21 to 26, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones, or wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters, or wherein the plurality of sidelink anchors is distributedacross the plurality of sidelink zones based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone, or a combination thereof.

Clause 28. The method of any of clauses 21 to 27, wherein the pluralityof sidelink zones comprises at least one dead zone where Uu-basedposition estimation does not satisfy an accuracy requirement.

Clause 29. A position estimation entity, comprising: a memory; at leastone transceiver; and at least one processor communicatively coupled tothe memory and the at least one transceiver, the at least one processorconfigured to: perform sidelink anchor registration with a plurality ofsidelink anchors distributed throughout a plurality of sidelink zones;transmit, via the at least one transceiver, to the plurality of sidelinkanchors and a user equipment (UE), a set of proximity-based sidelinkpositioning reference signal (PRS) pre-configurations for on-demand PRSposition estimation; and receive, via the at least one transceiver, oneor more measurement reports associated with an on-demand sidelink PRSposition estimation session between the UE and a dynamic sidelink anchorgroup that is determined in accordance with the set of proximity-basedsidelink PRS pre-configurations.

Clause 30. The position estimation entity of clause 29, wherein theplurality of sidelink zones is associated with a non-public network(NPN).

Clause 31. The position estimation entity of any of clauses 29 to 30,wherein each proximity-based sidelink PRS pre-configuration of the setof proximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 32. The position estimation entity of any of clauses 29 to 31,wherein the set of proximity-based sidelink PRS pre-configurations isbased at least in part upon a number of sidelink zones among theplurality of sidelink zones.

Clause 33. The position estimation entity of any of clauses 29 to 32,wherein the set of proximity-based sidelink PRS pre-configurationscomprises one or more sidelink zone-specific parameters.

Clause 34. The position estimation entity of any of clauses 29 to 33,wherein the at least one processor is further configured to: select theplurality of sidelink anchors based on a sidelink anchor constraint thatlimits a number of sidelink anchors assigned per sidelink zone.

Clause 35. The position estimation entity of clause 34, wherein theselection is based on one or more of UE capability, mobility status,power supply, position estimation accuracy, or a combination thereof.

Clause 36. The position estimation entity of any of clauses 29 to 35,wherein the plurality of sidelink zones comprises at least one dead zonewhere Uu-based position estimation does not satisfy an accuracyrequirement.

Clause 37. The position estimation entity of clause 36, wherein theposition estimation entity instructs the UE to trigger the on-demandsidelink PRS position estimation session upon entry into the at leastone dead zone, or wherein the position estimation entity triggers theon-demand sidelink PRS position estimation session upon detection thatthe UE has entered into the at least one dead zone.

Clause 38. A user equipment (UE), comprising: a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: receive, via the at least one transceiver, from aposition estimation entity, a set of proximity-based sidelinkpositioning reference signal (PRS) pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; transmit, via theat least one transceiver, a sidelink PRS trigger to trigger an on-demandsidelink PRS position estimation session with a dynamic sidelink anchorgroup, the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; and perform a sidelinkPRS exchange with the dynamic sidelink anchor group in association withthe on-demand sidelink PRS position estimation session based on one ormore proximity-based sidelink PRS pre-configurations from the set ofproximity-based sidelink PRS pre-configurations.

Clause 39. The UE of clause 38, wherein the at least one processor isfurther configured to: determine one or more beams for the sidelink PRSexchange based on a spatial relationship between the sidelink zoneassociated with the UE and one or more sidelink zones associated withthe dynamic sidelink anchor group.

Clause 40. The UE of any of clauses 38 to 39, wherein the proximityrequirement designates a maximum distance from the sidelink zoneassociated with the UE, a minimum distance from the sidelink zoneassociated with the UE, or a combination thereof.

Clause 41. The UE of any of clauses 38 to 40, wherein the sidelink PRSexchange comprises blind decoding or descrambling for sidelink PRS fromthe dynamic sidelink anchor group in accordance with a zone-specificsequence, or wherein the sidelink PRS exchange comprises selectivedecoding or descrambling for sidelink PRS from the dynamic sidelinkanchor group based on feedback to the sidelink PRS trigger from thedynamic sidelink anchor group.

Clause 42. The UE of any of clauses 38 to 41, wherein the plurality ofsidelink zones is associated with a non-public network (NPN).

Clause 43. The UE of any of clauses 38 to 42, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 44. The UE of any of clauses 38 to 43, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones.

Clause 45. The UE of any of clauses 38 to 44, wherein the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters.

Clause 46. The UE of any of clauses 38 to 45, wherein the plurality ofsidelink anchors is distributed across the plurality of sidelink zonesbased on a sidelink anchor constraint that limits a number of sidelinkanchors assigned per sidelink zone.

Clause 47. The UE of any of clauses 38 to 46, wherein the plurality ofsidelink zones comprises at least one dead zone where Uu-based positionestimation does not satisfy an accuracy requirement.

Clause 48. The UE of clause 47, wherein the position estimation entityinstructs the UE to trigger the on-demand sidelink PRS positionestimation session upon entry into the at least one dead zone, orwherein the position estimation entity triggers the on-demand sidelinkPRS position estimation session upon detection that the UE has enteredinto the at least one dead zone.

Clause 49. A sidelink anchor, comprising: a memory; at least onetransceiver; and at least one processor communicatively coupled to thememory and the at least one transceiver, the at least one processorconfigured to: perform sidelink anchor registration with a positionestimation entity; receive, via the at least one transceiver, from theposition estimation entity, a set of proximity-based sidelink PRSpre-configurations for on-demand PRS position estimation, the set ofproximity-based sidelink PRS pre-configurations associated with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; receive, via the at least one transceiver, from a userequipment (UE), a sidelink PRS trigger to trigger an on-demand sidelinkPRS position estimation session with a dynamic sidelink anchor group,the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; determine that thesidelink anchor satisfies the proximity requirement to the sidelinkzone; select at least one proximity-based sidelink PRS pre-configurationfrom the set of proximity-based sidelink PRS pre-configurations based ona proximity between the sidelink anchor and the sidelink zone associatedwith the UE; perform a sidelink PRS exchange with the UE associated withthe on-demand sidelink PRS position estimation session based on thedetermination and in accordance with the at least one selectedproximity-based sidelink PRS pre-configuration.

Clause 50. The sidelink anchor of clause 49, wherein the at least oneprocessor is further configured to: determine one or more beams for thesidelink PRS exchange based on a spatial relationship between thesidelink zone associated with the UE and a sidelink zone associated withthe sidelink anchor.

Clause 51. The sidelink anchor of any of clauses 49 to 50, wherein theproximity requirement designates a maximum distance from the sidelinkzone associated with the UE, a minimum distance from the sidelink zoneassociated with the UE, or a combination thereof.

Clause 52. The sidelink anchor of any of clauses 49 to 51, wherein theat least one processor is further configured to: transmit, via the atleast one transceiver, a response to the sidelink PRS trigger tofacilitate the sidelink PRS exchange between the UE and the sidelinkanchor.

Clause 53. The sidelink anchor of any of clauses 49 to 52, wherein theplurality of sidelink zones is associated with a non-public network(NPN).

Clause 54. The sidelink anchor of any of clauses 49 to 53, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 55. The sidelink anchor of any of clauses 49 to 54, wherein theset of proximity-based sidelink PRS pre-configurations is based at leastin part upon a number of sidelink zones among the plurality of sidelinkzones, or wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters, or wherein the plurality of sidelink anchors is distributedacross the plurality of sidelink zones based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone, or a combination thereof.

Clause 56. The sidelink anchor of any of clauses 49 to 55, wherein theplurality of sidelink zones comprises at least one dead zone whereUu-based position estimation does not satisfy an accuracy requirement.

Clause 57. A position estimation entity, comprising: means forperforming sidelink anchor registration with a plurality of sidelinkanchors distributed throughout a plurality of sidelink zones; means fortransmitting, to the plurality of sidelink anchors and a user equipment(UE), a set of proximity-based sidelink positioning reference signal(PRS) pre-configurations for on-demand PRS position estimation; andmeans for receiving one or more measurement reports associated with anon-demand sidelink PRS position estimation session between the UE and adynamic sidelink anchor group that is determined in accordance with theset of proximity-based sidelink PRS pre-configurations.

Clause 58. The position estimation entity of clause 57, wherein theplurality of sidelink zones is associated with a non-public network(NPN).

Clause 59. The position estimation entity of any of clauses 57 to 58,wherein each proximity-based sidelink PRS pre-configuration of the setof proximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 60. The position estimation entity of any of clauses 57 to 59,wherein the set of proximity-based sidelink PRS pre-configurations isbased at least in part upon a number of sidelink zones among theplurality of sidelink zones.

Clause 61. The position estimation entity of any of clauses 57 to 60,wherein the set of proximity-based sidelink PRS pre-configurationscomprises one or more sidelink zone-specific parameters.

Clause 62. The position estimation entity of any of clauses 57 to 61,further comprising: means for selecting the plurality of sidelinkanchors based on a sidelink anchor constraint that limits a number ofsidelink anchors assigned per sidelink zone.

Clause 63. The position estimation entity of clause 62, wherein theselection is based on one or more of UE capability, mobility status,power supply, position estimation accuracy, or a combination thereof.

Clause 64. The position estimation entity of any of clauses 57 to 63,wherein the plurality of sidelink zones comprises at least one dead zonewhere Uu-based position estimation does not satisfy an accuracyrequirement.

Clause 65. The position estimation entity of clause 64, wherein theposition estimation entity instructs the UE to trigger the on-demandsidelink PRS position estimation session upon entry into the at leastone dead zone, or wherein the position estimation entity triggers theon-demand sidelink PRS position estimation session upon detection thatthe UE has entered into the at least one dead zone.

Clause 66. A user equipment (UE), comprising: means for receiving, froma position estimation entity, a set of proximity-based sidelinkpositioning reference signal (PRS) pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; means fortransmitting a sidelink PRS trigger to trigger an on-demand sidelink PRSposition estimation session with a dynamic sidelink anchor group, thesidelink PRS trigger configured to indicate a sidelink zone associatedwith the UE and a proximity requirement for participation in theon-demand sidelink PRS position estimation; and means for performing asidelink PRS exchange with the dynamic sidelink anchor group inassociation with the on-demand sidelink PRS position estimation sessionbased on one or more proximity-based sidelink PRS pre-configurationsfrom the set of proximity-based sidelink PRS pre-configurations.

Clause 67. The UE of clause 66, further comprising: means fordetermining one or more beams for the sidelink PRS exchange based on aspatial relationship between the sidelink zone associated with the UEand one or more sidelink zones associated with the dynamic sidelinkanchor group.

Clause 68. The UE of any of clauses 66 to 67, wherein the proximityrequirement designates a maximum distance from the sidelink zoneassociated with the UE, a minimum distance from the sidelink zoneassociated with the UE, or a combination thereof.

Clause 69. The UE of any of clauses 66 to 68, wherein the sidelink PRSexchange comprises blind decoding or descrambling for sidelink PRS fromthe dynamic sidelink anchor group in accordance with a zone-specificsequence, or wherein the sidelink PRS exchange comprises selectivedecoding or descrambling for sidelink PRS from the dynamic sidelinkanchor group based on feedback to the sidelink PRS trigger from thedynamic sidelink anchor group.

Clause 70. The UE of any of clauses 66 to 69, wherein the plurality ofsidelink zones is associated with a non-public network (NPN).

Clause 71. The UE of any of clauses 66 to 70, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 72. The UE of any of clauses 66 to 71, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones.

Clause 73. The UE of any of clauses 66 to 72, wherein the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters.

Clause 74. The UE of any of clauses 66 to 73, wherein the plurality ofsidelink anchors is distributed across the plurality of sidelink zonesbased on a sidelink anchor constraint that limits a number of sidelinkanchors assigned per sidelink zone.

Clause 75. The UE of any of clauses 66 to 74, wherein the plurality ofsidelink zones comprises at least one dead zone where Uu-based positionestimation does not satisfy an accuracy requirement.

Clause 76. The UE of clause 75, wherein the position estimation entityinstructs the UE to trigger the on-demand sidelink PRS positionestimation session upon entry into the at least one dead zone, orwherein the position estimation entity triggers the on-demand sidelinkPRS position estimation session upon detection that the UE has enteredinto the at least one dead zone.

Clause 77. A sidelink anchor, comprising: means for performing sidelinkanchor registration with a position estimation entity; means forreceiving, from the position estimation entity, a set of proximity-basedsidelink PRS pre-configurations for on-demand PRS position estimation,the set of proximity-based sidelink PRS pre-configurations associatedwith a plurality of sidelink anchors distributed throughout a pluralityof sidelink zones; means for receiving, from a user equipment (UE), asidelink PRS trigger to trigger an on-demand sidelink PRS positionestimation session with a dynamic sidelink anchor group, the sidelinkPRS trigger configured to indicate a sidelink zone associated with theUE and a proximity requirement for participation in the on-demandsidelink PRS position estimation; means for determining that thesidelink anchor satisfies the proximity requirement to the sidelinkzone; means for selecting at least one proximity-based sidelink PRSpre-configuration from the set of proximity-based sidelink PRSpre-configurations based on a proximity between the sidelink anchor andthe sidelink zone associated with the UE; means for performing asidelink PRS exchange with the UE associated with the on-demand sidelinkPRS position estimation session based on the determination and inaccordance with the at least one selected proximity-based sidelink PRSpre-configuration.

Clause 78. The sidelink anchor of clause 77, further comprising: meansfor determining one or more beams for the sidelink PRS exchange based ona spatial relationship between the sidelink zone associated with the UEand a sidelink zone associated with the sidelink anchor.

Clause 79. The sidelink anchor of any of clauses 77 to 78, wherein theproximity requirement designates a maximum distance from the sidelinkzone associated with the UE, a minimum distance from the sidelink zoneassociated with the UE, or a combination thereof.

Clause 80. The sidelink anchor of any of clauses 77 to 79, furthercomprising: means for transmitting a response to the sidelink PRStrigger to facilitate the sidelink PRS exchange between the UE and thesidelink anchor.

Clause 81. The sidelink anchor of any of clauses 77 to 80, wherein theplurality of sidelink zones is associated with a non-public network(NPN).

Clause 82. The sidelink anchor of any of clauses 77 to 81, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.

Clause 83. The sidelink anchor of any of clauses 77 to 82, wherein theset of proximity-based sidelink PRS pre-configurations is based at leastin part upon a number of sidelink zones among the plurality of sidelinkzones, or wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters, or wherein the plurality of sidelink anchors is distributedacross the plurality of sidelink zones based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone, or a combination thereof.

Clause 84. The sidelink anchor of any of clauses 77 to 83, wherein theplurality of sidelink zones comprises at least one dead zone whereUu-based position estimation does not satisfy an accuracy requirement.

Clause 85. A non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a positionestimation entity, cause the position estimation entity to: performsidelink anchor registration with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; transmit, to theplurality of sidelink anchors and a user equipment (UE), a set ofproximity-based sidelink positioning reference signal (PRS)pre-configurations for on-demand PRS position estimation; and receiveone or more measurement reports associated with an on-demand sidelinkPRS position estimation session between the UE and a dynamic sidelinkanchor group that is determined in accordance with the set ofproximity-based sidelink PRS pre-configurations.

Clause 86. The non-transitory computer-readable medium of clause 85,wherein the plurality of sidelink zones is associated with a non-publicnetwork (NPN).

Clause 87. The non-transitory computer-readable medium of any of clauses85 to 86, wherein each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

Clause 88. The non-transitory computer-readable medium of any of clauses85 to 87, wherein the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

Clause 89. The non-transitory computer-readable medium of any of clauses85 to 88, wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

Clause 90. The non-transitory computer-readable medium of any of clauses85 to 89, further comprising instructions that, when executed byposition estimation entity, further cause the position estimation entityto: select the plurality of sidelink anchors based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone.

Clause 91. The non-transitory computer-readable medium of clause 90,wherein the selection is based on one or more of UE capability, mobilitystatus, power supply, position estimation accuracy, or a combinationthereof.

Clause 92. The non-transitory computer-readable medium of any of clauses85 to 91, wherein the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.

Clause 93. The non-transitory computer-readable medium of clause 92,wherein the position estimation entity instructs the UE to trigger theon-demand sidelink PRS position estimation session upon entry into theat least one dead zone, or wherein the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

Clause 94. A non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a user equipment(UE), cause the UE to: receive, from a position estimation entity, a setof proximity-based sidelink positioning reference signal (PRS)pre-configurations for on-demand PRS position estimation, the set ofproximity-based sidelink PRS pre-configurations associated with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; transmit a sidelink PRS trigger to trigger an on-demandsidelink PRS position estimation session with a dynamic sidelink anchorgroup, the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; and perform a sidelinkPRS exchange with the dynamic sidelink anchor group in association withthe on-demand sidelink PRS position estimation session based on one ormore proximity-based sidelink PRS pre-configurations from the set ofproximity-based sidelink PRS pre-configurations.

Clause 95. The non-transitory computer-readable medium of clause 94,further comprising instructions that, when executed by UE, further causethe UE to: determine one or more beams for the sidelink PRS exchangebased on a spatial relationship between the sidelink zone associatedwith the UE and one or more sidelink zones associated with the dynamicsidelink anchor group.

Clause 96. The non-transitory computer-readable medium of any of clauses94 to 95, wherein the proximity requirement designates a maximumdistance from the sidelink zone associated with the UE, a minimumdistance from the sidelink zone associated with the UE, or a combinationthereof.

Clause 97. The non-transitory computer-readable medium of any of clauses94 to 96, wherein the sidelink PRS exchange comprises blind decoding ordescrambling for sidelink PRS from the dynamic sidelink anchor group inaccordance with a zone-specific sequence, or wherein the sidelink PRSexchange comprises selective decoding or descrambling for sidelink PRSfrom the dynamic sidelink anchor group based on feedback to the sidelinkPRS trigger from the dynamic sidelink anchor group.

Clause 98. The non-transitory computer-readable medium of any of clauses94 to 97, wherein the plurality of sidelink zones is associated with anon-public network (NPN).

Clause 99. The non-transitory computer-readable medium of any of clauses94 to 98, wherein each proximity-based sidelink PRS pre-configuration ofthe set of proximity-based sidelink PRS pre-configurations designates asidelink PRS frequency layer, a first offset from a sidelink PRS triggerfrom the UE to a sidelink PRS transmission from the respective sidelinkanchor, an expected reception time of sidelink PRS from the UE, a combtype, a muting pattern, or a combination thereof.

Clause 100. The non-transitory computer-readable medium of any ofclauses 94 to 99, wherein the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.

Clause 101. The non-transitory computer-readable medium of any ofclauses 94 to 100, wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.

Clause 102. The non-transitory computer-readable medium of any ofclauses 94 to 101, wherein the plurality of sidelink anchors isdistributed across the plurality of sidelink zones based on a sidelinkanchor constraint that limits a number of sidelink anchors assigned persidelink zone.

Clause 103. The non-transitory computer-readable medium of any ofclauses 94 to 102, wherein the plurality of sidelink zones comprises atleast one dead zone where Uu-based position estimation does not satisfyan accuracy requirement.

Clause 104. The non-transitory computer-readable medium of clause 103,wherein the position estimation entity instructs the UE to trigger theon-demand sidelink PRS position estimation session upon entry into theat least one dead zone, or wherein the position estimation entitytriggers the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.

Clause 105. A non-transitory computer-readable medium storingcomputer-executable instructions that, when executed by a sidelinkanchor, cause the sidelink anchor to: perform sidelink anchorregistration with a position estimation entity; receive, from theposition estimation entity, a set of proximity-based sidelink PRSpre-configurations for on-demand PRS position estimation, the set ofproximity-based sidelink PRS pre-configurations associated with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; receive, from a user equipment (UE), a sidelink PRStrigger to trigger an on-demand sidelink PRS position estimation sessionwith a dynamic sidelink anchor group, the sidelink PRS triggerconfigured to indicate a sidelink zone associated with the UE and aproximity requirement for participation in the on-demand sidelink PRSposition estimation; determine that the sidelink anchor satisfies theproximity requirement to the sidelink zone; select at least oneproximity-based sidelink PRS pre-configuration from the set ofproximity-based sidelink PRS pre-configurations based on a proximitybetween the sidelink anchor and the sidelink zone associated with theUE; perform a sidelink PRS exchange with the UE associated with theon-demand sidelink PRS position estimation session based on thedetermination and in accordance with the at least one selectedproximity-based sidelink PRS pre-configuration.

Clause 106. The non-transitory computer-readable medium of clause 105,further comprising instructions that, when executed by sidelink anchor,further cause the sidelink anchor to: determine one or more beams forthe sidelink PRS exchange based on a spatial relationship between thesidelink zone associated with the UE and a sidelink zone associated withthe sidelink anchor.

Clause 107. The non-transitory computer-readable medium of any ofclauses 105 to 106, wherein the proximity requirement designates amaximum distance from the sidelink zone associated with the UE, aminimum distance from the sidelink zone associated with the UE, or acombination thereof.

Clause 108. The non-transitory computer-readable medium of any ofclauses 105 to 107, further comprising instructions that, when executedby sidelink anchor, further cause the sidelink anchor to: transmit aresponse to the sidelink PRS trigger to facilitate the sidelink PRSexchange between the UE and the sidelink anchor.

Clause 109. The non-transitory computer-readable medium of any ofclauses 105 to 108, wherein the plurality of sidelink zones isassociated with a non-public network (NPN).

Clause 110. The non-transitory computer-readable medium of any ofclauses 105 to 109, wherein each proximity-based sidelink PRSpre-configuration of the set of proximity-based sidelink PRSpre-configurations designates a sidelink PRS frequency layer, a firstoffset from a sidelink PRS trigger from the UE to a sidelink PRStransmission from the respective sidelink anchor, an expected receptiontime of sidelink PRS from the UE, a comb type, a muting pattern, or acombination thereof.

Clause 111. The non-transitory computer-readable medium of any ofclauses 105 to 110, wherein the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones, or wherein the set ofproximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters, or wherein the plurality of sidelinkanchors is distributed across the plurality of sidelink zones based on asidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone, or a combination thereof.

Clause 112. The non-transitory computer-readable medium of any ofclauses 105 to 111, wherein the plurality of sidelink zones comprises atleast one dead zone where Uu-based position estimation does not satisfyan accuracy requirement.

Those of skill in the art will appreciate that information and signalsmay be represented using any of a variety of different technologies andtechniques. For example, data, instructions, commands, information,signals, bits, symbols, and chips that may be referenced throughout theabove description may be represented by voltages, currents,electromagnetic waves, magnetic fields or particles, optical fields orparticles, or any combination thereof.

Further, those of skill in the art will appreciate that the variousillustrative logical blocks, modules, circuits, and algorithm stepsdescribed in connection with the aspects disclosed herein may beimplemented as electronic hardware, computer software, or combinationsof both. To clearly illustrate this interchangeability of hardware andsoftware, various illustrative components, blocks, modules, circuits,and steps have been described above generally in terms of theirfunctionality. Whether such functionality is implemented as hardware orsoftware depends upon the particular application and design constraintsimposed on the overall system. Skilled artisans may implement thedescribed functionality in varying ways for each particular application,but such implementation decisions should not be interpreted as causing adeparture from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits describedin connection with the aspects disclosed herein may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an ASIC, a field-programmable gate array (FPGA), or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices,for example, a combination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration.

The methods, sequences and/or algorithms described in connection withthe aspects disclosed herein may be embodied directly in hardware, in asoftware module executed by a processor, or in a combination of the two.A software module may reside in random access memory (RAM), flashmemory, read-only memory (ROM), erasable programmable ROM (EPROM),electrically erasable programmable ROM (EEPROM), registers, hard disk, aremovable disk, a CD-ROM, or any other form of storage medium known inthe art. An example storage medium is coupled to the processor such thatthe processor can read information from, and write information to, thestorage medium. In the alternative, the storage medium may be integralto the processor. The processor and the storage medium may reside in anASIC. The ASIC may reside in a user terminal (e.g., UE). In thealternative, the processor and the storage medium may reside as discretecomponents in a user terminal.

In one or more example aspects, the functions described may beimplemented in hardware, software, firmware, or any combination thereof.If implemented in software, the functions may be stored on ortransmitted over as one or more instructions or code on acomputer-readable medium. Computer-readable media includes both computerstorage media and communication media including any medium thatfacilitates transfer of a computer program from one place to another. Astorage media may be any available media that can be accessed by acomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM or other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium that can be used to carry or store desired program code inthe form of instructions or data structures and that can be accessed bya computer. Also, any connection is properly termed a computer-readablemedium. For example, if the software is transmitted from a website,server, or other remote source using a coaxial cable, fiber optic cable,twisted pair, digital subscriber line (DSL), or wireless technologiessuch as infrared, radio, and microwave, then the coaxial cable, fiberoptic cable, twisted pair, DSL, or wireless technologies such asinfrared, radio, and microwave are included in the definition of medium.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and Blu-ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects of thedisclosure, it should be noted that various changes and modificationscould be made herein without departing from the scope of the disclosureas defined by the appended claims. The functions, steps and/or actionsof the method claims in accordance with the aspects of the disclosuredescribed herein need not be performed in any particular order.Furthermore, although elements of the disclosure may be described orclaimed in the singular, the plural is contemplated unless limitation tothe singular is explicitly stated.

What is claimed is:
 1. A method of operating a position estimationentity, comprising: performing sidelink anchor registration with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; transmitting, to the plurality of sidelink anchors and auser equipment (UE), a set of proximity-based sidelink positioningreference signal (PRS) pre-configurations for on-demand PRS positionestimation; and receiving one or more measurement reports associatedwith an on-demand sidelink PRS position estimation session between theUE and a dynamic sidelink anchor group that is determined in accordancewith the set of proximity-based sidelink PRS pre-configurations.
 2. Themethod of claim 1, wherein the plurality of sidelink zones is associatedwith a non-public network (NPN).
 3. The method of claim 1, wherein eachproximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.
 4. The method of claim 1,wherein the set of proximity-based sidelink PRS pre-configurations isbased at least in part upon a number of sidelink zones among theplurality of sidelink zones.
 5. The method of claim 1, wherein the setof proximity-based sidelink PRS pre-configurations comprises one or moresidelink zone-specific parameters.
 6. The method of claim 1, furthercomprising: selecting the plurality of sidelink anchors based on asidelink anchor constraint that limits a number of sidelink anchorsassigned per sidelink zone.
 7. The method of claim 6, wherein theselection is based on one or more of UE capability, mobility status,power supply, position estimation accuracy, or a combination thereof. 8.The method of claim 1, wherein the plurality of sidelink zones comprisesat least one dead zone where Uu-based position estimation does notsatisfy an accuracy requirement.
 9. The method of claim 8, furthercomprising: instructing the UE to trigger the on-demand sidelink PRSposition estimation session upon entry into the at least one dead zone,or triggering the on-demand sidelink PRS position estimation sessionupon detection that the UE has entered into the at least one dead zone.10. A method of operating a user equipment (UE), comprising: receiving,from a position estimation entity, a set of proximity-based sidelinkpositioning reference signal (PRS) pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; transmitting asidelink PRS trigger to trigger an on-demand sidelink PRS positionestimation session with a dynamic sidelink anchor group, the sidelinkPRS trigger configured to indicate a sidelink zone associated with theUE and a proximity requirement for participation in the on-demandsidelink PRS position estimation; and performing a sidelink PRS exchangewith the dynamic sidelink anchor group in association with the on-demandsidelink PRS position estimation session based on one or moreproximity-based sidelink PRS pre-configurations from the set ofproximity-based sidelink PRS pre-configurations.
 11. The method of claim10, further comprising: determining one or more beams for the sidelinkPRS exchange based on a spatial relationship between the sidelink zoneassociated with the UE and one or more sidelink zones associated withthe dynamic sidelink anchor group.
 12. The method of claim 10, whereinthe proximity requirement designates a maximum distance from thesidelink zone associated with the UE, a minimum distance from thesidelink zone associated with the UE, or a combination thereof.
 13. Themethod of claim 10, wherein performing the sidelink PRS exchangecomprises blind decoding or descrambling for sidelink PRS from thedynamic sidelink anchor group in accordance with a zone-specificsequence, or wherein performing the sidelink PRS exchange comprisesselective decoding or descrambling for sidelink PRS from the dynamicsidelink anchor group based on feedback to the sidelink PRS trigger fromthe dynamic sidelink anchor group.
 14. The method of claim 10, whereinthe plurality of sidelink zones is associated with a non-public network(NPN).
 15. The method of claim 10, wherein each proximity-based sidelinkPRS pre-configuration of the set of proximity-based sidelink PRSpre-configurations designates a sidelink PRS frequency layer, a firstoffset from a sidelink PRS trigger from the UE to a sidelink PRStransmission from the respective sidelink anchor, an expected receptiontime of sidelink PRS from the UE, a comb type, a muting pattern, or acombination thereof.
 16. The method of claim 10, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones.
 17. The method of claim 10, wherein the set of proximity-basedsidelink PRS pre-configurations comprises one or more sidelinkzone-specific parameters.
 18. The method of claim 10, wherein theplurality of sidelink anchors is distributed across the plurality ofsidelink zones based on a sidelink anchor constraint that limits anumber of sidelink anchors assigned per sidelink zone.
 19. The method ofclaim 10, wherein the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.
 20. The method of claim 19, wherein the UE isinstructed by the position estimation entity to trigger the on-demandsidelink PRS position estimation session upon entry into the at leastone dead zone, or wherein the on-demand sidelink PRS position estimationsession is triggered upon detection that the UE has entered into the atleast one dead zone.
 21. A method of operating a sidelink anchor,comprising: performing sidelink anchor registration with a positionestimation entity; receiving, from the position estimation entity, a setof proximity-based sidelink PRS pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; receiving, from auser equipment (UE), a sidelink PRS trigger to trigger an on-demandsidelink PRS position estimation session with a dynamic sidelink anchorgroup, the sidelink PRS trigger configured to indicate a sidelink zoneassociated with the UE and a proximity requirement for participation inthe on-demand sidelink PRS position estimation; determining that thesidelink anchor satisfies the proximity requirement to the sidelinkzone; selecting at least one proximity-based sidelink PRSpre-configuration from the set of proximity-based sidelink PRSpre-configurations based on a proximity between the sidelink anchor andthe sidelink zone associated with the UE; and performing a sidelink PRSexchange with the UE associated with the on-demand sidelink PRS positionestimation session based on the determination and in accordance with theat least one selected proximity-based sidelink PRS pre-configuration.22. The method of claim 21, further comprising: determining one or morebeams for the sidelink PRS exchange based on a spatial relationshipbetween the sidelink zone associated with the UE and a sidelink zoneassociated with the sidelink anchor.
 23. The method of claim 21, whereinthe proximity requirement designates a maximum distance from thesidelink zone associated with the UE, a minimum distance from thesidelink zone associated with the UE, or a combination thereof.
 24. Themethod of claim 21, further comprising: transmitting a response to thesidelink PRS trigger to facilitate the sidelink PRS exchange between theUE and the sidelink anchor.
 25. The method of claim 21, wherein theplurality of sidelink zones is associated with a non-public network(NPN).
 26. The method of claim 21, wherein each proximity-based sidelinkPRS pre-configuration of the set of proximity-based sidelink PRSpre-configurations designates a sidelink PRS frequency layer, a firstoffset from a sidelink PRS trigger from the UE to a sidelink PRStransmission from the respective sidelink anchor, an expected receptiontime of sidelink PRS from the UE, a comb type, a muting pattern, or acombination thereof.
 27. The method of claim 21, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones, or wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters, or wherein the plurality of sidelink anchors is distributedacross the plurality of sidelink zones based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone, or a combination thereof.
 28. The method of claim 21,wherein the plurality of sidelink zones comprises at least one dead zonewhere Uu-based position estimation does not satisfy an accuracyrequirement.
 29. A position estimation entity, comprising: a memory; atleast one transceiver; and at least one processor communicativelycoupled to the memory and the at least one transceiver, the at least oneprocessor configured to: perform sidelink anchor registration with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; transmit, via the at least one transceiver, to theplurality of sidelink anchors and a user equipment (UE), a set ofproximity-based sidelink positioning reference signal (PRS)pre-configurations for on-demand PRS position estimation; and receive,via the at least one transceiver, one or more measurement reportsassociated with an on-demand sidelink PRS position estimation sessionbetween the UE and a dynamic sidelink anchor group that is determined inaccordance with the set of proximity-based sidelink PRSpre-configurations.
 30. The position estimation entity of claim 29,wherein the plurality of sidelink zones is associated with a non-publicnetwork (NPN).
 31. The position estimation entity of claim 29, whereineach proximity-based sidelink PRS pre-configuration of the set ofproximity-based sidelink PRS pre-configurations designates a sidelinkPRS frequency layer, a first offset from a sidelink PRS trigger from theUE to a sidelink PRS transmission from the respective sidelink anchor,an expected reception time of sidelink PRS from the UE, a comb type, amuting pattern, or a combination thereof.
 32. The position estimationentity of claim 29, wherein the set of proximity-based sidelink PRSpre-configurations is based at least in part upon a number of sidelinkzones among the plurality of sidelink zones.
 33. The position estimationentity of claim 29, wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters.
 34. The position estimation entity of claim 29, wherein theat least one processor is further configured to: select the plurality ofsidelink anchors based on a sidelink anchor constraint that limits anumber of sidelink anchors assigned per sidelink zone.
 35. The positionestimation entity of claim 34, wherein the selection is based on one ormore of LIE capability, mobility status, power supply, positionestimation accuracy, or a combination thereof.
 36. The positionestimation entity of claim 29, wherein the plurality of sidelink zonescomprises at least one dead zone where Uu-based position estimation doesnot satisfy an accuracy requirement.
 37. The position estimation entityof claim 36, wherein the at least one processor is further configured toinstruct the UE to trigger the on-demand sidelink PRS positionestimation session upon entry into the at least one dead zone, orwherein the UE is triggered by the position estimation entity to performthe on-demand sidelink PRS position estimation session upon detectionthat the UE has entered into the at least one dead zone.
 38. A userequipment (UE), comprising: a memory; at least one transceiver; and atleast one processor communicatively coupled to the memory and the atleast one transceiver, the at least one processor configured to:receive, via the at least one transceiver, from a position estimationentity, a set of proximity-based sidelink positioning reference signal(PRS) pre-configurations for on-demand PRS position estimation, the setof proximity-based sidelink PRS pre-configurations associated with aplurality of sidelink anchors distributed throughout a plurality ofsidelink zones; transmit, via the at least one transceiver, a sidelinkPRS trigger to trigger an on-demand sidelink PRS position estimationsession with a dynamic sidelink anchor group, the sidelink PRS triggerconfigured to indicate a sidelink zone associated with the UE and aproximity requirement for participation in the on-demand sidelink PRSposition estimation; and perform a sidelink PRS exchange with thedynamic sidelink anchor group in association with the on-demand sidelinkPRS position estimation session based on one or more proximity-basedsidelink PRS pre-configurations from the set of proximity-based sidelinkPRS pre-configurations.
 39. The UE of claim 38, wherein the at least oneprocessor is further configured to: determine one or more beams for thesidelink PRS exchange based on a spatial relationship between thesidelink zone associated with the UE and one or more sidelink zonesassociated with the dynamic sidelink anchor group.
 40. The UE of claim38, wherein the proximity requirement designates a maximum distance fromthe sidelink zone associated with the UE, a minimum distance from thesidelink zone associated with the UE, or a combination thereof.
 41. TheUE of claim 38, wherein, to perform the sidelink PRS exchange, the atleast one processor is configured to perform blind decoding ordescrambling for sidelink PRS from the dynamic sidelink anchor group inaccordance with a zone-specific sequence, or wherein, to perform thesidelink PRS exchange, the at least one processor is configured toperform selective decoding or descrambling for sidelink PRS from thedynamic sidelink anchor group based on feedback to the sidelink PRStrigger from the dynamic sidelink anchor group.
 42. The UE of claim 38,wherein the plurality of sidelink zones is associated with a non-publicnetwork (NPN).
 43. The UI of claim 38, wherein each proximity-basedsidelink PRS pre-configuration of the set of proximity-based sidelinkPRS pre-configurations designates a sidelink PRS frequency layer, afirst offset from a sidelink PRS trigger from the UE to a sidelink PRStransmission from the respective sidelink anchor, an expected receptiontime of sidelink PRS from the UE, a comb type, a muting pattern, or acombination thereof.
 44. The UE of claim 38, wherein the set ofproximity-based sidelink PRS pre-configurations is based at least inpart upon a number of sidelink zones among the plurality of sidelinkzones.
 45. The UE of claim 38, wherein the set of proximity-basedsidelink PRS pre-configurations comprises one or more sidelinkzone-specific parameters.
 46. The UE of claim 38, wherein the pluralityof sidelink anchors is distributed across the plurality of sidelinkzones based on a sidelink anchor constraint that limits a number ofsidelink anchors assigned per sidelink zone.
 47. The UE of claim 38,wherein the plurality of sidelink zones comprises at least one dead zonewhere Uu-based position estimation does not satisfy an accuracyrequirement.
 48. The UE of claim 47, wherein the UE is instructed by theposition estimation entity to trigger the on-demand sidelink PRSposition estimation session upon entry into the at least one dead zone,or wherein the UE is triggered by the position estimation entity toperform the on-demand sidelink PRS position estimation session upondetection that the UE has entered into the at least one dead zone.
 49. Asidelink anchor, comprising: a memory; at least one transceiver; and atleast one processor communicatively coupled to the memory and the atleast one transceiver, the at least one processor configured to: performsidelink anchor registration with a position estimation entity; receive,via the at least one transceiver, from the position estimation entity, aset of proximity-based sidelink PRS pre-configurations for on-demand PRSposition estimation, the set of proximity-based sidelink PRSpre-configurations associated with a plurality of sidelink anchorsdistributed throughout a plurality of sidelink zones; receive, via theat least one transceiver, from a user equipment (UE), a sidelink PRStrigger to trigger an on-demand sidelink PRS position estimation sessionwith a dynamic sidelink anchor group, the sidelink PRS triggerconfigured to indicate a sidelink zone associated with the UE and aproximity requirement for participation in the on-demand sidelink PRSposition estimation; determine that the sidelink anchor satisfies theproximity requirement to the sidelink zone; select at least oneproximity-based sidelink PRS pre-configuration from the set ofproximity-based sidelink PRS pre-configurations based on a proximitybetween the sidelink anchor and the sidelink zone associated with theUE; perform a sidelink PRS exchange with the UE associated with theon-demand sidelink PRS position estimation session based on thedetermination and in accordance with the at least one selectedproximity-based sidelink PRS pre-configuration.
 50. The sidelink anchorof claim 49, wherein the at least one processor is further configuredto: determine one or more beams for the sidelink PRS exchange based on aspatial relationship between the sidelink zone associated with the UEand a sidelink zone associated with the sidelink anchor.
 51. Thesidelink anchor of claim 49, wherein the proximity requirementdesignates a maximum distance from the sidelink zone associated with theUE, a minimum distance from the sidelink zone associated with the UE, ora combination thereof.
 52. The sidelink anchor of claim 49, wherein theat least one processor is further configured to: transmit, via the atleast one transceiver, a response to the sidelink PRS trigger tofacilitate the sidelink PRS exchange between the UE and the sidelinkanchor.
 53. The sidelink anchor of claim 49, wherein the plurality ofsidelink zones is associated with a non-public network (NPN).
 54. Thesidelink anchor of claim 49, wherein each proximity-based sidelink PRSpre-configuration of the set of proximity-based sidelink PRSpre-configurations designates a sidelink PRS frequency layer, a firstoffset from a sidelink PRS trigger from the UE to a sidelink PRStransmission from the respective sidelink anchor, an expected receptiontime of sidelink PRS from the UE, a comb type, a muting pattern, or acombination thereof.
 55. The sidelink anchor of claim 49, wherein theset of proximity-based sidelink PRS pre-configurations is based at leastin part upon a number of sidelink zones among the plurality of sidelinkzones, or wherein the set of proximity-based sidelink PRSpre-configurations comprises one or more sidelink zone-specificparameters, or wherein the plurality of sidelink anchors is distributedacross the plurality of sidelink zones based on a sidelink anchorconstraint that limits a number of sidelink anchors assigned persidelink zone, or a combination thereof.
 56. The sidelink anchor ofclaim 49, wherein the plurality of sidelink zones comprises at least onedead zone where Uu-based position estimation does not satisfy anaccuracy requirement.